Silly Questions

[lakedrifter]

So, still new to all this, but I had some question for the beginner.

I have noticed that GM used 2 different ecm designs between 1987 and 1992

1987/90 - 24 and 32 pin connector
1991/92 - 32 and 32 pin connector

I think that's right:)
What were the differences between the 2? Are both OBD1?

Are the ALDL ports for them different?


lakedrifter

[Randy 79]

It may depend on the computer more than years. For example, my 92 7060 ecu has a 32 and 24 pin connector. OBD1 would be 95 and earlier.

[fastacton]

If you're talking truck ECMs like the '7747 (black connectors), it was the 24/32 pin style from '87 through '92. In '91 the '7060 (brown connectors) came on the scene through '93 and was still a 24/32 pin setup. In '93, the '7427 style ECM (red/blue connectors) came along and was the 32/32 pin setup through '95. They are all OBD1 and the ALDL uses the same connector, but different pins depending on the ECM.

[lakedrifter]

Thanks for the info guys. Yes it was a truck that I removed the ECM from.

I have the red/blue connectors, I guess I should go back and grab the ALDL from the vehicle I took the ECM from. That way the ALDL pin-out will be correct.

A couple more questions, but It’s more of a process out-line.

EFI install


Go through my wiring harness and label everything.
Install my TBI (after I rebuild it of course) w/IAC and TPS
Install my O2 sensor (I’m using a single wire for now)
Install my Fuel Pump (My original tank is bad so I will get a new one that is made for the in-tank fuel pump)
Remove manual fuel pump and install block off plate.
My Knock Sensor (83’) appears to be the same as from the EFI years.
Install my HEI Distributor w/EST and Coil
Install the ESC
Install my Relays
My air cleaner has the MAP sensor attached.
Install New water temp sensor at the water neck location
My van already has a VSS because of the cruise control (It’s the Yellow box behind the Dash). I’m not sure if it will work.
Install EGR solenoid. I have this already. My 700r4 used a Bleed solenoid to help with Lockup. GMs recommended replacement was the EGR solenoid.
Install my wiring harness


ECM


Load Tuner Pro on my Laptop
Download the correct BIN for the vehicle I working on.
Use the USB to ALDL interface to flash the EPROM with appropriate BIN (tune)
If I want to fine tune or make changes, Make them in tuner pro and re flash the EPROM




Did I leave anything out of the process?
What do I do with the wires for the transmission? will any of them be used for the TC lockup?
Is my original Knock sensor usable?


lakedrifter

[lionelhutz]

MAP - should go to manifold vacuum, not the air cleaner
EGR - has nothing to do with the TCC lockup.
Tunerpro - can't flash the EPROM. You need a programmer.
The new ECM should be able to control the TCC better than a vacuum switch or whatever else you're using.
No idea on the knock sensor. There are generally 2 types, the 4k ohms and 100k ohms, and which one is used depends on the ECM.

[lakedrifter]

MAP - should go to manifold vacuum, not the air cleaner. Its just attached to it (as in mounting location) and not connected to it.


EGR - has nothing to do with the TCC lockup. You are correct, I had it confused with a delay valve.

The 700r4 lockup is controled by a vacuum switch (Single wire to the transmission) and a delay valve. So I will have to figure that part and how it works with the ECM.


You need a programmer. Ok I fugured out what that is now:)

[JP86SS]

ECM:
For TunerPro you need 3 things

1.) Editor Definition "XDF" FILE for your "Mask ID" ($0D or $E6 whatever yours is running)
2.) Datastream (Logging) Definition "ADX" file (also for the Mask ID you have)
3.) Bin file (your running program if you want to make changes and reprogram. Otherwise not needed.
Then a logging cable and a chip programmer or emulator.

[lakedrifter]

ECM:
For TunerPro you need 3 things

1.) Editor Definition "XDF" FILE for your "Mask ID" ($0D or $E6 whatever yours is running)
2.) Datastream (Logging) Definition "ADX" file (also for the Mask ID you have)
3.) Bin file (your running program if you want to make changes and reprogram. Otherwise not needed.
Then a logging cable and a chip programmer or emulator.


With that being said, tuner pro with the bin, mask and data logging file utilizes the programmer if you want to change the eprrom?

The programmer is just the hard interface to the eprom from your pc/laptop?

[lakedrifter]

ECM:
For TunerPro you need 3 things

1.) Editor Definition "XDF" FILE for your "Mask ID" ($0D or $E6 whatever yours is running)
2.) Datastream (Logging) Definition "ADX" file (also for the Mask ID you have)
3.) Bin file (your running program if you want to make changes and reprogram. Otherwise not needed.
Then a logging cable and a chip programmer or emulator.


With that being said, tuner pro with the bin, mask and data logging file utilizes the programmer if you want to change the eprrom?

The programmer is just the hard interface to the eprom from your pc/laptop?

[lionelhutz]

Tunerpro would interface to a emulator which replaces the EPROM to emulate it. The advantage is that real time changes are possible with an emulator.

You'd use the programming software that came with the EPROM burner if you went that way.

[lakedrifter]

Tunerpro would interface to a emulator which replaces the EPROM to emulate it. The advantage is that real time changes are possible with an emulator.

You'd use the programming software that came with the EPROM burner if you went that way.

That makes more sense.

So if I want to just leave my ECM alone. knowing that I came out of a similar vehicle. Whats the chances of it working correctly?

[lakedrifter]

ok, last silly question.

When I was at the junkyard, I pulled a wiring harness and equipment from a 92 GM. Some one had already grabbed the ECM:) It dawned on me when the drivers seat kept wobbling around.

I ended up pulling a 5.0 ECM (16197427) from a 95 GM.

I could deffinatley tell the difference between the Wiring harness and the ECM harness, because the wire count is off by atleast 10.

My question is, can I still use this ECM with this wiring harness, just by mapping the wiring harness to the correct ECM pin? Will the ECM allow me to do that? Would this be considered a conversion from 1227747 to 16197427?

lakedrifter

[fastacton]

Yes, it would be considered a conversion and would be a good way to go. Just grab some red/blue connectors and swap the wires over, there are a couple of threads about how to do it here.

[lakedrifter]

Thanks alot for all the help. I grabbed the red and blue when I took the ECM, so I will get to sorting:)

Thanks again everyone..

[Fast355]

Its just attached to it (as in mounting location) and not connected to it.

You are correct, I had it confused with a delay valve.

The 700r4 lockup is controled by a vacuum switch (Single wire to the transmission) and a delay valve. So I will have to figure that part and how it works with the ECM.

Ok I fugured out what that is now:)

Your OEM setup sounds exactly like my 1983 G20 Van LE9 305 with the 700r4. Converted it to TBI from a 92 G20 and replaced the stock transmission with the 92 G20 trans after building it.

EGR Bleed Solenoid DOES have a part in the TCC circuit of an 83 G20.

You will have to completely rewire and reconfigure the pressure switches to have the ECM control the lockup of your early 700r4.

[Fast355]

Thanks for the info guys. Yes it was a truck that I removed the ECM from.

I have the red/blue connectors, I guess I should go back and grab the ALDL from the vehicle I took the ECM from. That way the ALDL pin-out will be correct.

A couple more questions, but It’s more of a process out-line.

EFI install


Go through my wiring harness and label everything.
Install my TBI (after I rebuild it of course) w/IAC and TPS
Install my O2 sensor (I’m using a single wire for now)
Install my Fuel Pump (My original tank is bad so I will get a new one that is made for the in-tank fuel pump)
Remove manual fuel pump and install block off plate.
My Knock Sensor (83’) appears to be the same as from the EFI years.
Install my HEI Distributor w/EST and Coil
Install the ESC
Install my Relays
My air cleaner has the MAP sensor attached.
Install New water temp sensor at the water neck location
My van already has a VSS because of the cruise control (It’s the Yellow box behind the Dash). I’m not sure if it will work.
Install EGR solenoid. I have this already. My 700r4 used a Bleed solenoid to help with Lockup. GMs recommended replacement was the EGR solenoid.
Install my wiring harness


ECM


Load Tuner Pro on my Laptop
Download the correct BIN for the vehicle I working on.
Use the USB to ALDL interface to flash the EPROM with appropriate BIN (tune)
If I want to fine tune or make changes, Make them in tuner pro and re flash the EPROM




Did I leave anything out of the process?
What do I do with the wires for the transmission? will any of them be used for the TC lockup?
Is my original Knock sensor usable?


lakedrifter

I integrated my factory harness and the TBI harness together. My floorboard had the correct hole and wire protection piece for the TBI harness existing. I swapped over to the TBI oil pressure sending unit and coolant temperature sender. I used the TBI intake after grinding the 4 center holes oblong. TBI tank and fuel lines went right in place of my stock ones and I reused the donor vans fuel pump wiring. I stole the factory choke heater power wire as the constant hot power source for the ECM. I stole the choke light in the cluster for a check engine light. I spliced into the VSS signal for my cruise. I replaced my knock sensor because it broke when I tried to remove the ESC systems original connector. For a long time I simply let the TCC lockup as it had stock with the vacuum switch, delay and thermostat housing mounted thermal vacuum valve. The TVS also controlled the stock air cleaner heat valve. When the stock 700r4 died I rebuilt the donor trans and added computer control to the lockup. You want the coolant temp sensor installed on the backside of the thermostat not after it. Otherwise it will high idle and run really rich until the thernostat opens then rapidly drop in idle speed and possibly stall. Ask me how I know that one! I used an 84' Camaro Crossfire 305 94a alternator in place of my stock 63a alternator and kept the V-Belts and massive A6 compressor for a while. I was running a 1991 or 1992 Caprice ECM and added an IAT circuit, P/S pressure switch, and WOT A/C shut-off relay for better driveability. As time progressed I swapped in a 350 with the donors serpentine setup and later on a vortec head TPI.

[lakedrifter]

Fast355... Dude you are in the money. Thats exactly my setup. Cuddos on the info, it will be very helpful.

I just figured out today that i could use my built in vss. :)

As for the intake i was just going to use mine with a adapter plate.

Alot of this is food for thought. I may have more quetions if you don't mind when the time comes.

Thanks for the info...

Lakedrifter

[Fast355]

Fast355... Dude you are in the money. Thats exactly my setup. Cuddos on the info, it will be very helpful.

I just figured out today that i could use my built in vss. :)

As for the intake i was just going to use mine with a adapter plate.

Alot of this is food for thought. I may have more quetions if you don't mind when the time comes.

Thanks for the info...

Lakedrifter

I have done the intake/adapter plate method and it works well, provided you are not running EGR. I drilled and tapped the back of my projection adapter for the power brake vacuum tube, the vacuum fuel pressure regulator and cruise control vacuum hose.

http://i243.photobucket.com/albums/ff172/Fast355_album/100_0717.jpg (http://s243.photobucket.com/user/Fast355_album/media/100_0717.jpg.html)

http://i243.photobucket.com/albums/ff172/Fast355_album/In1.jpg (http://s243.photobucket.com/user/Fast355_album/media/In1.jpg.html)

[Fast355]

One other thing if you can get the TBI manifolds and Y-pipe in the junkyard, they have larger exits, 3" after the Y instead of 2.5", no smog tubes, delete the EFE valve and have an 02 sensor bung on the driverside. I had a little 204/214 @ .050 RV cam in my 305 and woke it up noticeably.

[lakedrifter]

Does that mean Ill have to omit the EGR completely if I want to use the TBI adapter plate? Or it just won't be able to allow the ECM to control it via the EGR solenoid? I thought the 92 EGR was still controlled by vacuum and supplied by the EGR solenoid which was controlled by the ECM?

[lakedrifter]

That 92 g20 is there still. I think ill go pull the intake and the headers with y pipe, fuel lines. I was gonna take the tank but the punch holes in them on the bottom. I wasnt sure if i could get it sealed up. I did pull the fuel pump already.

[Fast355]

That 92 g20 is there still. I think ill go pull the intake and the headers with y pipe, fuel lines. I was gonna take the tank but the punch holes in them on the bottom. I wasnt sure if i could get it sealed up. I did pull the fuel pump already.

I bought the whole van before it made it to a yard. Fuel tank should be affordible on RockAuto or Amazon.

The EGR valve and IAC motor are fighting for the same space with the Holley Projection TBI adapter. The GM 454 TBI adapter might be better.

[lakedrifter]

I bought the whole van before it made it to a yard. Fuel tank should be affordible on RockAuto or Amazon.

The EGR valve and IAC motor are fighting for the same space with the Holley Projection TBI adapter. The GM 454 TBI adapter might be better.

i didnt thi nk about the IAC sticking if to the side. I think im gonna pull that 92 intake since the engeneering is already there.

What size fuel tank is yours. When i looked on amazon i only found for efi on the van was 22 gallon. My current one is 33.

[Fast355]

i didnt thi nk about the IAC sticking if to the side. I think im gonna pull that 92 intake since the engeneering is already there.

What size fuel tank is yours. When i looked on amazon i only found for efi on the van was 22 gallon. My current one is 33.

33 for both my 83 and the 1992 donor. Just looked it up on Rock Auto for a 1993 G20 and they have two different brands of 33 gallon tanks. Both are under $150.

[Fast355]

I knew I had some pictures somewhere. This was a marine TBI which was a 2" 454 late model style throttle body. The IAC is shorter on it than a smallblock TBI unit and it still collided with the EGR. Not to mention the Edelbrock Performer intake is a good 1/2" taller than stock.

http://i243.photobucket.com/albums/ff172/Fast355_album/6.jpg (http://s243.photobucket.com/user/Fast355_album/media/6.jpg.html)

http://i243.photobucket.com/albums/ff172/Fast355_album/7.jpg (http://s243.photobucket.com/user/Fast355_album/media/7.jpg.html)

[lionelhutz]

You could probably find the internal wire harness for a TBI 700R4 to convert it and it's probably not that expensive. Check online rebuilder parts sources. That might be easier than trying to re-wire it yourself.

[lakedrifter]

But if I pull the 92 G20 intake and since the TBI came from it. I shouldn't have any interference issues? It should be a direct bolt on.

[Fast355]

But if I pull the 92 G20 intake and since the TBI came from it. I shouldn't have any interference issues? It should be a direct bolt on.

You will have to elongate the 4 center bolt holes and fabricate/buy a spacer bushing so the the bolt has good clamping force. GM revised the bolt angle from 90° to the face of the head on the old engines to 72° on the 86+ engines.

[lakedrifter]

You will have to elongate the 4 center bolt holes and fabricate/buy a spacer bushing so the the bolt has good clamping force. GM revised the bolt angle from 90° to the face of the head on the old engines to 72° on the 86+ engines.

So the Head Face and Intake Face are still the same, the 4 center bolt hole angles on the 86+ engines are set at 72 degrees instead of 90 degree from previous years. You oblonged the 4 center bolt holes in the intake to allow access to the head threads that are at 90 degrees and shimmed the holes you drilled so they would bite enough to seal the intake? I think I have that right:)

This is probably going to be my best bet since I have to run an EGR.

[lionelhutz]

You need the EGR for emmissions? Getting rid of it and running the carb adapter plate gives you better intake choices and makes headers easier if you do upgrades in the future.

[lakedrifter]

I thought every state had to run EGR? This will be a daily driver.

[Fast355]

I thought every state had to run EGR? This will be a daily driver.

Techically it is a federal law. That being said my Marine intake on my L31 Express lacks EGR.

[lakedrifter]

Techically it is a federal law. That being said my Marine intake on my L31 Express lacks EGR.

;) Id get caught, lol. I think I can make the 92 intake work. I have my 305 marine on the stand and will use it to mock up what I need to do on the intake using that as a guide. slow and steady wins the race:)

On another note, I think I'll leave my 700r4 hooked up the way it is for now as well. I read the 700r4 lockup rewire thread. haha that was a lot to take in.

[lionelhutz]

You're not supposed to remove it but depending where you are depends on getting caught or not. Some states do no emissions checking at all and other states have regular visual and tail pipe and/or ODBII port checks.

[lakedrifter]

So what would omitting the EGR involve? If it saves me some work or money. who knows.

[lionelhutz]

Basically you just turn it off when you're creating a new bin file.

[lakedrifter]

Block off plate and turn off the egr in the ecm. Got it..

[lakedrifter]

Will the heads bolt on from a 92 Chevy G20 so I can use the intake without having to fix the 4 center bolts?

[Fast355]

Will the heads bolt on from a 92 Chevy G20 so I can use the intake without having to fix the 4 center bolts?

If they are from a 350 and you currently have a 305, you will lose about 1/2 to 1 full point of compression depending on if you have 53cc 601 heads or 58cc 416 heads currently on your 305. The TBI 350 heads are 65.3cc chambers. Other than that they will bolt on just fine. You would also need the self aligning rocker arms and valve covers off the 92 van.

At that point you might as well grab the whole 350, provided that is not why the van was in the wrecking yard and it is clean inside.

[lakedrifter]

I think I'm just going to try getting the intake to work on my set up first. I'f I fail then I can go grab a set of 305 heads that will work and another intake.

I'm still on a budget and I need a rear end more then the 350 at the moment. I've been chasing a ghost vibration that sounds like a cattle guard at 50/70mph. Whatever it is its finally starting to show its face, so maybe I'll find it this evening. If it is the rear end that 92' has one in it, I'm just not sure if the Gearing is different and what it will effect.

[lakedrifter]

Hey Guys, I hope everyone is doing well. I'm back with more silly questions lol.

So I scored a Chevy 5.7 TBI, wiring harness (24/32 pin) and 700r4 tranny in a "horse trade". (No ECM, UGGGGGHHH!!!)

I've been trying to figure out as much as I can on it, because I removed it from only the frame. The cab and bed had been removed and the engine and tranny were covered with a tarp. So no VIN.

What I know.
1) Supposedly it was an 89 Chevy with a 5.7.
2) The lug pattern was 6 bolt, I believe this would make it a C2500.
3) The Transmission serial number shows it to be a 700r4/4L60 built in 1987.

I can't really afford to jump into tuning and such and I just want to get my van to run a little better. A little more efficiently would be great. Quadrajets are a love hate relationship, and recently it seems more of hate than love. lol

I have most of the Mechanical worked out for this swap, but I am struggling with the ECM. The book shows 1227747 or a 1228747. From what I can tell it looks like it should have been a 1228747 because it is a 5.7. The wiring diagrams I research from here for the 2 look identical to me, but I haven't gone through them with a finer tooth comb yet. As for the EPROM "code" I certainly don't have a clue as to what it might be.

Can someone help with other identifying factors that would help reverse engineer my Frankenstein?

[fastacton]

I'd think it's more likely that it had the 7747. As far as harnesses go, you can use either ECM (plus a couple others), but the 7747 is more widely used and I'm not sure that the '8747 was ever used with the 700R4.

[lakedrifter]

I'd think it's more likely that it had the 7747. As far as harnesses go, you can use either ECM (plus a couple others), but the 7747 is more widely used and I'm not sure that the '8747 was ever used with the 700R4.

The ECM should be fairly easy to find, our wrench apart is full of TBIs, with that being said, finding one with the right chip;) thats another story. The original wiring harness I pulled was from a 1992 g20 but some one had already pulled the ECM. According to the 1227747 info page I need either an AMUR or a AYUB.

[fastacton]

ASDU is normally recommended as a starter for a 5.7/700R4 application when using the '7747. It's the most mature of the factory tunes.

[lakedrifter]

ASDU is normally recommended as a starter for a 5.7/700R4 application when using the '7747. It's the most mature of the factory tunes.

Thanks fastacton... I'll add that to my list. I'm head to the JY this saturday.

[lakedrifter]

Last silly question for the day. lol

With regaurds to Throtle Position Sensors I have notice a difference in connectors between 89' and 92'. The 89' has a smaller round 3 pin connector and the 92' has a larger flat 3 pin connector. Other than that, they should still function the same correct?

[fastacton]

It's actually the reverse. They went to the smaller round connector (metripack) in '90, I believe. They both work the same and use the same wire colors, but they don't bolt up to the same throttle bodies.

[lakedrifter]

Hmmmm. that is highly interesting. I'm going to have to check the the wiring harness donor in the junkyard this weekend. Maybe it wasn't a 92.

[Fast355]

ASDU is normally recommended as a starter for a 5.7/700R4 application when using the '7747. It's the most mature of the factory tunes.

I don't use ASDU in Van applications. A van runs better with an OEM van calibration.

[buddrow]

If you watch the knock counts and adjust spark as necessary the ASDU is a very capable bin in most applications from my experience, it is at least a good starter.

[Fast355]

If you watch the knock counts and adjust spark as necessary the ASDU is a very capable bin in most applications from my experience, it is at least a good starter.

I prefer ARJT or AYUB for a van or a 1992 AWLD. All run better than ASDU ever thought about. I am not an ASDU fan at all as it was setup for a 2.73 geared truck.

[lakedrifter]

yeah someone already pulled the one g20 ecm that would have worked the easiest.

[lakedrifter]

Ok, back to silly questions:) I hope I dont seem nagging to anyone.

While disecting all the diagrams trying to make it easier on myself. I find myself pondering on these. Everything else I have pretty straight.

1) What is an Electronic Air Control Valve (1227747, Pin C2)? I know what an IAC is but when I search to familiarize myself with the EAC, Im always lead back to the TBI and the IAC.

2) What are the most common locations to pick up the ECM fuse block terminations (ECM B and ECM/IGN). If its just Battery and Ignition circuits I can manage that but is there a better, cleaner, easier solution?

[fastacton]

1) is for applications that have air injection (smog pump). Most applications that I've dealt with don't even have it, I think I see it on about one out of 5 harnesses.

2) the fused power wires are normally ignition hot (pink/black for ECM and red for injectors, near ECM connectors), the battery power comes in off a fusable link (orange wire near fuel pump relay). If you're running a DRAC/VSSB or heated O2 sensor, they will have their own ignition hot wires as well.

[lakedrifter]

Ok, maybe I wasn't so clear on the Fuel system lol. Found a good video though.

I was missing the Secondary FP fail over from Oil Pressure Sensor, FP test port and Fuel Cycler Module:)

Now I get most of it...

Circuit assets identified
Fuel Pump Relay: Check
Fuel Cycler Module: Check
Fuel Test port: Check
Oil Pressure Switch: Check
Fuel Pump: Check
ECM pins: A1 and B2

Orange is the "Hot in Run" feed to the FP Relay and the Oil pressure switch. The ECM B2 is signal to the FP relays switch side (requires a crank signal?) to activate the FP in Run.

GM integrated a secondary fail over - If no power from relay to fuel pump the oil pressure switch will engage the Fuel pump via hydraulic switch at 4lbs causing the fuel pump to run.

The last piece I don’t get is Fuel Cycle Module, is this the “Key On” 2 second FP primer shot? It is pin A1 of the ECM.

Side note - Extremely long cranking times is an indicator of a possible bad fuel pump relay.

[lakedrifter]

I stumbled across an issue today. Can someone tell me the difference between a 3 wire esc and a 4 wire esc?

Dark Blue - Knock
Black- ECM
Brown - Ground

Yellow/red - ?
Red/Black - ?
Brown - Ground?
Blue - Knock?

[fastacton]

I haven't seen a 3 wire ESC for '7747 style ECM use. Here's the colors I see most often and where they go (not in any particular order):

pink/blk - key on +12v
yellow/red - to ECM
brown - ground
blue - knock sensor

[Fast355]

I stumbled across an issue today. Can someone tell me the difference between a 3 wire esc and a 4 wire esc?

Dark Blue - Knock
Black- ECM
Brown - Ground

Yellow/red - ?
Red/Black - ?
Brown - Ground?
Blue - Knock?

Don't recall mine having a 3-wire.

I may have the Brown and Black swapped. Been way too long since I messed with it to bypass it during my 7427 swap.

Dk Blue = Knock
Black = ECM
Brown = Ground
Pink/Blk = +12 VDC Keyed

[lakedrifter]

I'm hoping all my issues are resolved today. I love junkyards.

I stumbled across fresh meat today. 1990 G20 vin K. ECM and wiring harness are all intact:). I grabbed the ECM today and will be going back tomorrow for the rest. I had some obligations this afternoon.

1227747 with the correct Chip

[1project2many]

The last piece I don’t get is Fuel Cycle Module, is this the “Key On” 2 second FP primer shot? It is pin A1 of the ECM.

You're finding terms that GM doesn't generally use. I believe this refers to the "hot fuel handling module" used on some trucks to circulate fuel for up to 20 seconds. Old GM literature said the module could circulate fuel after the key was shut off but folks on the net seem to believe it simply extends the pump prime time. Either way it's not found on most trucks.


GM integrated a secondary fail over - If no power from relay to fuel pump the oil pressure switch will engage the Fuel pump via hydraulic switch at 4lbs causing the fuel pump to run.
Although pump relay failures were rare with these systems, often the only clue to a bad relay was extended crank times after a long "off" period.

I also don't remember a KS module which did not require external power (i.e. 3 wire). Do you have a link to the diagram or information you are referencing?

[lakedrifter]

You're finding terms that GM doesn't generally use. I believe this refers to the "hot fuel handling module" used on some trucks to circulate fuel for up to 20 seconds. Old GM literature said the module could circulate fuel after the key was shut off but folks on the net seem to believe it simply extends the pump prime time. Either way it's not found on most trucks.


You are correct. It is the hot fuel handling module. I have been combing various wiring diagrams, because of my various parts. Engine from and wiring harness from an 89 k2500, 92 g20 wiring harness. I think I was making it way to hard on myself. GM did use the term Fuel Cycle Module but I'd have to go back and look through all my diagrams.


I also don't remember a KS module which did not require external power (i.e. 3 wire). Do you have a link to the diagram or information you are referencing?

Again I was mixed between diagrams.

I really should have started with the ECM and worked my way backwards lol.

Tomorrow, I will have a complete TBI system that will work for me. It is a 90 G20, 5.7 with a 700r4. I pulled the ECM today to void off the vultures. I will acquire the complete harness tomorrow along with some other bells and whistles:)

[lakedrifter]

Well after 3.5 hours of junkyard time, I finally have me a complete ECM and harness that makes sense:)

Other Goodies I scored
1) 8.5 10 bolt with 30 spline axles (my 28 spline has had issues since I've owned it)
2) The fuse block and interior harness, because my fuse block has seen better days
3) Instrument panel. It was less than a cute CEL light, and the speed sensor from the transmission.
4) Reese hidden hitch. (I actually hit my head on it before I noticed it)
5) Aluminum drive shaft

Has anyone ever seen a vehicle equipped with an ABS controller but not equiped with ABS? I pulled the controller since it was attached to my harness, but there was nothing going down to any of the hubs.

[fastacton]

The early ABS didn't have wheel speed sensors. It just went off of the VSS input.

[lakedrifter]

The early ABS didn't have wheel speed sensors. It just went off of the VSS input.

Then I will leave it intact.

Ill have to go back and see what there was on the hydraulic side.

[lakedrifter]

Would it be this one? Kelsey Hayes RWAL anti-lock braking systems (ABS)

[Fast355]

Would it be this one? Kelsey Hayes RWAL anti-lock braking systems (ABS)


Yes it would be! RWAL setup. Should have a brain box under the top of the driver fender and an actuator in line to the rear wheel cylinders in the proportioning valve area.

[lakedrifter]

Yes it would be! RWAL setup. Should have a brain box under the top of the driver fender and an actuator in line to the rear wheel cylinders in the proportioning valve area.

Gotcha!

[lakedrifter]

Good afternoon everybody! Its been awhile since ive been on. I hope everyone is having a good year.

Im in the wrap up stage of my engine swap and everything has gone well. I ran across a snag. I am trying to pull the codes from the ecm, the book says to jumper the a and b terminals. I tried that and no code 12 diagnostics. The book shows the blk/wht as the actual ground. I tested the black white and it has ground on it. My question is whete does the white pin b wire go to? The diagram only shows a tan wire back to the ecm..

Thanks in advance.

Heath

[1project2many]

A connects to ground and B is the "Diagnostic Enable" circuit from the ECM. The ecm will only give codes if the engine is not running. If you install the jumper while the engine is running the ecm will use the CE light to indicate open or closed loop, and if closed it will indicate lean or rich operation.

[lakedrifter]

Thanks 1P2M, but I don't see one labeled "Diagnostic Enable" is that suppose to be pin A9 (24 pin connector)?

Heath

[lionelhutz]

What PCM are you using? You posted earlier you had a '7427 and you were re-wiring a harness to use it. But now it's completely unclear what you're actually working on besides you just mentioning the 24 pin connector which would indicate a '7747?

The white/black is typically the color for the diagnostic/test wire. It goes to A9 on the '7747 PCM.

[lakedrifter]

I'll have to check when I get home Lionel. I can't remember off the top of my head. its been awhile since I've looked at it other than hooking it up.

[lakedrifter]

oh wait, the '7427 is still in the box under my work table. that was the original 95 Van. Somewhere in the post I pulled a ECM for a 92 van in order to match the wiring harness I had, which is a '7747.

I'm betting on pin A9

Heath

[1project2many]

Heath, I apologize. Some of what I learned comes from the very early days of GM computers and CCC systems. As already mentioned, the correct wire would be found at A9 on a 1227747.

Shannen

[lakedrifter]

Thanks everyone, nothing wrong with that 1P2M. If you can shoot with a bent pool stick you can shoot with any pool stick. haha. What you mentioned earlier poses another question for me though. What are the Codes for open loop? You mentioned if you jump the A and B terminals with the engine running that the ECM would flash open and close loop info? My manual mentioned nothing about it, I didn't even know it could do it.

Heath

[1project2many]

There are no codes. The ecm will flash the check engine light at different frequencies for open vs closed loop. Fast flashing = open loop, slow flashing = closed loop. Once in closed loop you need to look at the duration of on-time vs off-time to determine rich or lean operation. If the light spends more time on then the O2 voltage is indicating rich exhaust.

[lakedrifter]

Thanks man! I appreciate the info. Last question. If i back probe the white/black in A9 with a paper clip, ground it and turn the key on. Its should start the ecm should start reporting. Right?

[1project2many]

Yes, grounding A9 should enable diagnostic mode.

[lakedrifter]

Thanks! I'll give it ago this evening.

[lakedrifter]

I tried grounding the A9 pin this evening. I couldnt get the ecm to go into diagnostic mode. Maybe the computer us bad?

[1project2many]

Possibly. It wouldn't flash any codes? Do you get the correct bulb check sequence at key on? When you turn the key on the CEL should light for a few seconds, shut off for a few seconds, then turn on and stay on.

[lakedrifter]

No, it would not. It did exactly as you described though. Key on, flash one time and then the CEL stayed on. I used a paper clip and a jumper wire with clips to ground it to a chassis ground. I also tried grounding it to one of the ECM grounds with just a paper clip. I had the same result both attempts.

Heath

[1project2many]

I don't know of a reason why the ecm would behave normally other than diagnostic mode. Did you have the key on while ground was applied?

[lakedrifter]

Yes, pin A9 was grounded and the key was on. I don't see a reason why either. I had read where during 95/96 when GM was moving to OBD2, there were a few OBD1 ECMs/Chip combos that you could not go into diagnostics mode by grounding A9 and that you had to use a scan tool. That shouldn't be my case though.

I had to pull the engine back out last night because it developed a knock. I tried installing new bearings myself. I should have known better:). I had the heads re-worked already. I'm taking the lower end to the machine shop tomorrow. I'll have to readdress this issue once I have it back in.

[lakedrifter]

My silly question for the day:))

Are all GM 1 wire temperature sensors the same? I mean shouldn't I find resistance on any 1 wire temperature sensor by testing between the connector and the body/tip of the sensor?

My 83 305 temperature sensor had 2k resistance between the pin and the body. It worked just fine.

I have gotten 2 now for the 89 and neither have any resistance. The first one I had in the van and my temp gauge wouldn't budge. I tested it and it read infinity. After I pulled the engine I went and had it swapped out for a new one and it reads infinity as well.

I did replace the cluster with a 89 cluster from the junkyard. If you ground the gauge it maxes out the needle as it should.

Heath

[1project2many]

The answers are "No" and "Yes, usually."

If you have a temperature sender for a warning light it will have infinite resistance (no continuity) until the sensor is at "too hot" temperature, then the sensor will have nearly zero resistance (high conductivity). It sounds like you need a sensor for a vehicle with a guage, not a light.

[lakedrifter]

uggggh! That never even dawned on me. Learn something new everyday.


Heath

[1project2many]

lol... and if you're like me, that means you forgot something important to make room.

[lakedrifter]

I've been fortunate in this project. This is no where near the complications that some of you guys tackle everyday. I'm just doing a direct TBI drop in from a 89/92 G20 to my 83 G20. I'm also swapping out the complete fuse box as well. 98% of the wire colors were the same and I had to splice in some old style connectors, but for the most part everything has been a success. I still have the Check engine light to contend with once I reinstall the motor.

I just can't understand why I have not been able to get the ECM to go to diagnostics mode by grounding A9 directly. At this point I'm suspecting the ECM itself since the CEL light acts normal when you go to Key On. I have about another 3 weeks until I can get back on that. My machine shop is a 2 man show and spring is here. They are kind of snowed under at the moment.

My last hurdle will be the transmission, when I had it rebuilt the tranny guy knew what I was planning. He said he rewired my 700r4 so that it was 4th gear lock up only, and that it would only unlock in 4th if the brake switch was applied. I'm hoping I don't have to do anything special to it after my harness replacement. Only time will tell.

[Fast355]

I've been fortunate in this project. This is no where near the complications that some of you guys tackle everyday. I'm just doing a direct TBI drop in from a 89/92 G20 to my 83 G20. I'm also swapping out the complete fuse box as well. 98% of the wire colors were the same and I had to splice in some old style connectors, but for the most part everything has been a success. I still have the Check engine light to contend with once I reinstall the motor.

I just can't understand why I have not been able to get the ECM to go to diagnostics mode by grounding A9 directly. At this point I'm suspecting the ECM itself since the CEL light acts normal when you go to Key On. I have about another 3 weeks until I can get back on that. My machine shop is a 2 man show and spring is here. They are kind of snowed under at the moment.

My last hurdle will be the transmission, when I had it rebuilt the tranny guy knew what I was planning. He said he rewired my 700r4 so that it was 4th gear lock up only, and that it would only unlock in 4th if the brake switch was applied. I'm hoping I don't have to do anything special to it after my harness replacement. Only time will tell.

My trans builder did that on the one 700r4 I had built back in the day. I HATED IT!!! In the van it tended to bog the engine on slight grades unless you really put your foot into it and caused it to downshift. I ended up picking up a a new factory GM lockup solenoid, pressure switch and wiring for a 1992 G20 van and put it all in place. This put the ECM in control of the lockup. The ECM locked the torque converter in 2nd, 3rd and 4th gear in relation to throttle position and vehicle speed. Driveability was MUCH better.

[lakedrifter]

My trans builder did that on the one 700r4 I had built back in the day. I HATED IT!!! In the van it tended to bog the engine on slight grades unless you really put your foot into it and caused it to downshift. I ended up picking up a a new factory GM lockup solenoid, pressure switch and wiring for a 1992 G20 van and put it all in place. This put the ECM in control of the lockup. The ECM locked the torque converter in 2nd, 3rd and 4th gear in relation to throttle position and vehicle speed. Driveability was MUCH better.

You know that is the exact issue I had with the 305 after the tranny was rebuilt. Another one of the reasons I wanted to upgrade, thinking that it was a HP issue.

I have all the wiring intact from the 1992. I know the Lock up solenoid between the 83 and 92 g20 have the same part number but I'm not looking up OEM though.

Considering the ECM for the 92 locks in 2nd, 3rd and 4th based on the computer, does that mean I need a pressure switch for 2nd and 3rd as well? There should be one already on 4th?

Heath

[Fast355]

You know that is the exact issue I had with the 305 after the tranny was rebuilt. Another one of the reasons I wanted to upgrade, thinking that it was a HP issue.

I have all the wiring intact from the 1992. I know the Lock up solenoid between the 83 and 92 g20 have the same part number but I'm not looking up OEM though.

Considering the ECM for the 92 locks in 2nd, 3rd and 4th based on the computer, does that mean I need a pressure switch for 2nd and 3rd as well? There should be one already on 4th?

Heath

The pressure switch for the computer controlled lockup is specific for ECM control. It tells the ECM if the transmission is in LOW (2nd & 3rd) or HIGH (4th) gear.

[1project2many]

and that it would only unlock in 4th if the brake switch was applied

Ohh.... that's not so good. I don't expect you to like that one.

[lakedrifter]

Im going to have to find a diagram inside the tranny and some photos. I think im confused now. There is only one lock up solenoid in the 700r4. And there is a pressure switch on the valve body at the 4th gear valve. Once the pressure switch senses 4th gear applied it sends a signal to the the lock up solenoid. To be able to have the computer control 2nd, 3rd and 4th for lock up. Wouldnt you have to have a pressure switch for each valve?

[lakedrifter]

I do know my wiring diagram shows a High Gear from the ECM to the Transmission.

[lakedrifter]

Ohh.... that's not so good. I don't expect you to like that one.

Heck no! it was terrible...

[Fast355]

3
Im going to have to find a diagram inside the tranny and some photos. I think im confused now. There is only one lock up solenoid in the 700r4. And there is a pressure switch on the valve body at the 4th gear valve. Once the pressure switch senses 4th gear applied it sends a signal to the the lock up solenoid. To be able to have the computer control 2nd, 3rd and 4th for lock up. Wouldnt you have to have a pressure switch for each valve?

Not at all....The ECM grounds the TCC solenoid. The switch merely tells the ECM when the trans is in 4th gear so that it will use the High Gear TCC tables and constants. I seem to remember a thermal switch as well that locks the converter when the trans is overheating.

[lakedrifter]

Oh that makes way more sense. I had it all jacked up in my head. Thats something i can work with. I appreciate the info.

[lionelhutz]

My trans builder did that on the one 700r4 I had built back in the day. I HATED IT!!! In the van it tended to bog the engine on slight grades unless you really put your foot into it and caused it to downshift. I ended up picking up a a new factory GM lockup solenoid, pressure switch and wiring for a 1992 G20 van and put it all in place. This put the ECM in control of the lockup. The ECM locked the torque converter in 2nd, 3rd and 4th gear in relation to throttle position and vehicle speed. Driveability was MUCH better.

I'll agree here. People will tell you it works great, but the reality is that most are manually shifting their setup out of 4th at times to avoid the double whammy of lockup and OD hitting at the same time, or they just have a switch to turn the lockup off when it's annoying them. The PCM does a very good job of controlling the TCC lockup, so just plan on using it.

[1project2many]

Before ecm/pcm control there were several switches used to control TCC operation including a brake switch, switches active in certain gears, and a vacuum switch. The thermal switch would bypass most of these in case the trans began to overheat and they are all on the ground side. The brake switch is usually wired to the powered side of the circuit, even in cars with ecm controlled TCC.

[Fast355]

Before ecm/pcm control there were several switches used to control TCC operation including a brake switch, switches active in certain gears, and a vacuum switch. The thermal switch would bypass most of these in case the trans began to overheat and they are all on the ground side. The brake switch is usually wired to the powered side of the circuit, even in cars with ecm controlled TCC.

The older pre-computer G-Vans had a vacuum switch that was connected to ported vacuum on the carb through a thermal vacuum valve on the thermostat housing and a vacuum delay valve. In 2nd and 3rd gear the vacuum switch controlled lockup. Around town with a cold engine there was no lockup until the engine got to about 120°F or you hit 4th gear. In 4th the trans locked via a pressure switch that also tied into an EGR bleed solenoid. EGR Bleed solenoid allowed the EGR valve to partially or fully close in overdrive by allowing filtered air from the rear of the carb into the EGR vacuum source. I did not much care for how the setup drove in stock form with only a 305 and 3.08 gears. It had the downshift blues and the shifts were pretty harsh with a locked converter.

[lakedrifter]

The older pre-computer G-Vans had a vacuum switch that was connected to ported vacuum on the carb through a thermal vacuum valve on the thermostat housing and a vacuum delay valve. In 2nd and 3rd gear the vacuum switch controlled lockup. Around town with a cold engine there was no lockup until the engine got to about 120°F or you hit 4th gear. In 4th the trans locked via a pressure switch that also tied into an EGR bleed solenoid. EGR Bleed solenoid allowed the EGR valve to partially or fully close in overdrive by allowing filtered air from the rear of the carb into the EGR vacuum source. I did not much care for how the setup drove in stock form with only a 305 and 3.08 gears. It had the downshift blues and the shifts were pretty harsh with a locked converter.

This is exactly how mine was setup as a stock 83 van. I didn't really notice what I considered poor shifting, but you guys would know better than me. I do know when I had it rebuilt and it was wired for single wire 4th lock up. It sucked!! Every time i'd climb a hill it would "what I thought" lock or unlock. I know the RPMs, would jump from 2500 to 3000. Once you got on the down hill side you would go back to normal. I'm really not sure if it was unlocking or down shifting to tell you the truth.

I would rather have the best drive ability I can, so I just have to install the original lock-up solenoid, pressure switch and rewire the guts of the transmission. I just need to find a diagram. The diagram in the book, show everything going to transmission. It never shows the solenoid or pressure switch and where they lay in the wiring harness:mad1: .

Even a simple pin layout will work. I believe its Pin A, B and C on the transmission connector that are used.

[lakedrifter]

So I have been researching most of the morning. I have come to the conclusion that TCC solenoids for GM come in various Types. Most notably in the 700r4. There appears to be about 6/9 versions or so. They are dictated by year/setup. Labeled by type and color.

The 1992 G20 takes a Type 18 (light brown).

Does anyone have an actual list of these Types w/descriptions?

[lakedrifter]

Let me rephrase.

When you look it up by Type, it has the same TCC solenoid the wiring and setups were different

Something along these lines
83 to 86 was a Type 1 White
87 was a Type 15 Dark green
88 - No type listed, just the universal TCC Solenoid
1989 to 92 was a Type 18 light brown
1993 went to 4l80E and a whole new can of worms.

[lionelhutz]

I've seen people quote the info so it seems it is documented.

The '7747 wiring shows the solenoid between A and D. The 4th gear switch is between B and ground. The temperature switch is between B and D so during a high temperature it would ground the solenoid when in overdrive.

[lakedrifter]

Yes i have only seen the "Type" on one other forum. I started checking parts list at rock auto, gm, and monster transmission. You will always see the TCC solenoid by itself, but if you look down it has it by type with the associated wiring and plug/connector If you keep looking you will find the pressure switch and the temp switch if any associated for that year. I think everyone is generally talking the same things, via hands on experience and what not. Im trying to break it down for my unexperienced brain.

I have an atsg manual coming. Im sure it will come together in the end. I also have an 89 700r4/4l60 im gonna pop the pan on to have a look see.

[Fast355]

I've seen people quote the info so it seems it is documented.

The '7747 wiring shows the solenoid between A and D. The 4th gear switch is between B and ground. The temperature switch is between B and D so during a high temperature it would ground the solenoid when in overdrive.

If memory serves me correctly the high gear switch is open in 4th and closed in 2nd and 3rd.

[lakedrifter]

This is a remake of a Type 18 TCC harness.

I do believe the red goes to the Ignition (Purple) of the Harness

I wasn't sure where the:

Tan/Black - Shift light\TCC control (Pin A7)

Lt Blue - High Gear Switch (Pin C7)

Went to in the mix

Heath

[lakedrifter]

Woo, I had that way out of wack. good thing for videos.

[lakedrifter]

Does anyone know how to test a 1 pole pressure switch to see what type it is? Normaly open or Normaly closed?

I suppose if it was known good then a resitance test would work?

[lionelhutz]

It goes A, D, B top to bottom, or the red is power, black is TCC control and white is 4th gear switch.

[lakedrifter]

Yes that is correct. I pulled the pan on the 86 and that how its wired.

[lakedrifter]

So i figured out the ecm today. For some reason in the g20, it dropped the white/black, orange and tan out of from the adl, down below the fuse box. I remember in the junk yard that they ran under the floor. It didnt dawn on me until today that they ran back to a 3 wire connector that plugged in close to the harness. Traced them out and thats what they were. Once the motor is back in ill test it again.

[lakedrifter]

Most of you probably know this stuff, but here it goes anyway....



700r4


Type
Model


3
TS, YF, YL, MH, TN, TR


4
FA, MA, MM, TJ, YK, YN,. YP, YT


6
MP, PL, TA, TB


9
YC, YD, YW, YX, YZ. YA, YR, YS


10
MW, TW


4L60


Type
Model


15
FAM, MAM,MDM, MFM, MKM, MLM, MMM, MPM, MRM, MUM, MWM, MXM, MZM, TYM, TKM, TUM, TXM


18
AAM, ADM, AFM, ASM, BAM, BBM, BCM, BHM, BRM, BWM, CPM, FAM, FDM, FRM, FXM, SFM


19
SAM


22
HBM, HDM, HJM, HLM


4l60E


Type
Model


23
FFM, FMM, YAM, YCM, YDM



Model identifies application, wiring type and engine size. I wish I had a list:) Each type has subtle differences. Most notable are the wiring, pressure switches, separator plate and addition of an auxiliary valve body. The pressure switches are all color coded. Which means they have different pressures at which they are switched open and closed. You also have different separator plates that will work.

[lakedrifter]

I wonder if this is why I hear most folks, even my tranny builder say. "Just wire it up for 4th gear lock-up!" in voice of Karl Childers:)

[lionelhutz]

You should try it then. I tried it and hated it, but what do I know? I will never run a 700R4 again. The 4L60e gives control over every gear and the lockup so I can make it do what I want without messing with the governor and valve body. Even then, with enough messing around you will reach a point with a 700R4 starts shifting OK most of the time yet still have areas where it's not what you actually want.

[lakedrifter]

Baby steps. Lol i may get there one day.

[Fast355]

You should try it then. I tried it and hated it, but what do I know? I will never run a 700R4 again. The 4L60e gives control over every gear and the lockup so I can make it do what I want without messing with the governor and valve body. Even then, with enough messing around you will reach a point with a 700R4 starts shifting OK most of the time yet still have areas where it's not what you actually want.

Electronically shifted transmissions are ALOT easier to tune. I would never run a 4L60E again for that matter unless it came in a vehicle and was still working well. As soon as it died, there would be a 4L80E swap performed.

[lakedrifter]

All good points, but I'm a poor man. Tuning is way down the road, haha. I'm just swapping. My best bet is to go with what it was stock as far as ECM, ENG, Transmission.

When I do get ready to go to a 4L80E, I don't believe I'm that far off. I have the ECM for it already, I'd just have to find a 4L80E and make the swap from the 7747 to the 7427, add the wiring to the transmission from the ECM. Should be a snap:) lol

[1project2many]

That's one of the disadvantages of living in an area where vehicles don't rust. Up here you can find 4L80E's in rusty vehicles and the whole vehicle runs $500.

[lakedrifter]

in my quest for knowledge, does anyone happen to know what this switch is and how it works on the 700r4/4l60?


NonGrounded Governor Lock-up delay switch

[lakedrifter]

Good morning gents. Im in the middle of putting my engine back in. I have a question. Im trying to time my engine and i know my timing is correct, firing order and plug wires correct. I cant get it to idle and i have alot of little back firing. You can hear the intak going crack......crack.......crack..........crack....

My question is my TPS sensor is only puttin about 2.4 volts with WOT. There is code 22 from the ecm. Can the faulty TPS cause all these idle issues.

Im also gettimg a knock sensor code 43, but i havent looked at it yet.

Please advise

Heath

[lakedrifter]

ok so I got it to Idle after I replaced the TPS. I also adjusted the valves. The Code 43 for the knock sensor is gone. For some odd ball reason the Code 22 for the TPS low voltage is still there.

Is there and adjustment to the TPS. It is not the type with slotted screw holes. looks to me like no adjustment. Anyone have any recommendations?

lakedrifter

[lakedrifter]

Well after a couple of hours of tracing, I finally figured it out. I had the Knock Sensor and TPS wires crossed. Didn't realize until I got back to the ECM under the seat. Swapped the Dark Blues and BOOM, no more check engine.