K1500 4.3 to 7.4 swap

[K1500ss4x4]

This is great! Hopefully this problem I'm having is something you've seen before.
I swapped engines in a 1995 K1500 4.3L 7427 PCM $OD 4L60E from Monster Transmission. Put in a 7.4L from a 1995 C3500 HD 7427 PCM $31 4l80E I only swapped the engine not the trans. or harness because I'm using the $OD mask PCM. I'm using TunerPro RT with an APU1/G1/ALD1 Several bins from TunerPro and one I adjusted from the original 4.3 memcal and these 0D_tpv5_v250.xdf (http://0d_tpv5_v250.xdf/) A217_0D_v250.adx (http://a217_0d_v250.adx/)

My issue is that I can't seem to get correct communication with the PCM, TunerPro and APU1/ALD1. Whenever I try to open the dashboard in the .adx file I only get engine temp readings which seem accurate, TPS readings in numeric form but no gage movement, no tach (I do get tach INSIDE the truck)
Sometimes I get wild fluctuations on all the gages. The idle is very high 2000 rpm (N). ONCE I was able to see all the readings including tach AND the idle was good at 850 rpm (N) But haven't been able to recreate this. Is it possible the PCM isn't recieving certain data like tach which is keeping it from regulating idle speed? Also the IAC may be a subject of concern, I have read in some forums that when swapping from a 4.3 or SBC to a BBC, the IAC wiring needs to change but I haven't been able to get an answer on what those changes are. I have wiring diagrams from ALLDATA and they show the wire colors being the same and wired the same. But that doesn't seem to be the problem because it did work correctly that one time.

Thanks so much for this forum, any help would be appreciated.

Bobby

[JeepsAndGuns]

Are you sure the pcm is not in limp home mode?

Am I understanding that you are using a 4.3 bin to run the 454?? What about the memcal? Are you also running the 4.3 memcal? I would highly reccomend running the 454 memcal. With them both being 95, they should both be either 16197427 or 16196395 pcm's, which will interchange. Ditch the 4.3 bin (an memcal if you are running it) and use the 7.4 bin and memcal. If you need to run a 4L60E with the 7.4, I think I remember seeing at one time on here, someone made a bin just for that.

[K1500ss4x4]

Thanks for the reply JeepsandGuns, I have been told by everyone I've talked to about this including Dave at Moates to use the 4.3 modded to 8 cyl and the correct displacement etc.. 1) because the $OD is running my transmission 2) the harness in the truck would need very little work. 3)The 7.4 had a linear EGR the 4.3 has a vacuum EGR. I disabled the EGR in the bin. How do know for sure if the PCM is in limp home mode? I was also told by Dave at Moates that if I am recieving data in TunerPro that I'm not in limp home mode. And it did seem to work that one time although it doesn't go into closed loop.

Thanks again!

[K1500ss4x4]

I looked around for a BIN file that contained a 7.4 and 4L60E but didn't find one that would've been great!

[EagleMark]

But Dave at Moates is a Ford guy!

Inside the Memcal is the chip which you are adjusting for the engine change. There is also a knock module which is wrong for your engine and netres or Limp Home chip which is wrong for your engine, it's also for a 6 cylinder. This alone may be your issue?

Looks like you have the correct ADX file. But you really need the newer XDF file (Advanced $0D TP5 v251.xdf) and then start with your original bin file and rework it. There were some issues with the XDF your using. Also to use the AutoProm Emulator you need to set the Mask ID to "AA" to disable checksum while emulating or even just running the bin from AutoProm.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-OD

Did Dave at Moates go over the AutoProm with you to make sure it is all set up and being operated properly? I'd suggest looking at the Moates AutoProm videoas to get familar. One thing though, you DO NOT want to place the switch for 10K outward for this PCM, both switches inward.
http://www.youtube.com/watch?v=GDzeSi5nmoo&list=PL0CA878598D87BA29

What does your CEL do when Key On Engine Off? Does it go off when engine is started?

Changing a 4.3L bin file to a 7.4L bin file is much more complicated then just changing displacement!!!

[EagleMark]

I looked around for a BIN file that contained a 7.4 and 4L60E but didn't find one that would've been great!That's because the 7.4L engine never came with a 4L60E transmission. Most all bin files we have here are stock files. What you need is a very custom built bin file, there's nothing simple about it. I have done them but it takes several hours... maybe a lot more for a beginner.

Still think your first and possibly main issue is the V6 Netres/LHM chip in your memcal. But I have never tested it, usually just start with correct parts.

One cation while your doing this so you don't have transmission issues is always use 94 for 94 trans and 95 for 95 trans as they are differant.

[K1500ss4x4]

Hi EagleMark

Thanks for that Yes I did enter AA in the Mask ID and the switches are in the correct position inward. I went over the videos at Moates. The CEL stays on. I wish Dave would have been more thorough he's kind of short tempered.... He and Brian Harris from Harris performance both told me to use the 4.3 bin modified. I'm confused now should I have saved the harness from the c3500 HD?

[K1500ss4x4]

When I originally taked to Moates they really made it sound like I could do it but now I'm starting to doubt it and The mechanical part is complete ready to run. OH NO!
I just don't understand how it ran so well that one time idled right.

[K1500ss4x4]

But Dave at Moates is a Ford guy!

Inside the Memcal is the chip which you are adjusting for the engine change. There is also a knock module which is wrong for your engine and netres or Limp Home chip which is wrong for your engine, it's also for a 6 cylinder. This alone may be your issue?

Looks like you have the correct ADX file. But you really need the newer XDF file (Advanced $0D TP5 v251.xdf) and then start with your original bin file and rework it. There were some issues with the XDF your using. Also to use the AutoProm Emulator you need to set the Mask ID to "AA" to disable checksum while emulating or even just running the bin from AutoProm.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-OD

Did Dave at Moates go over the AutoProm with you to make sure it is all set up and being operated properly? I'd suggest looking at the Moates AutoProm videoas to get familar. One thing though, you DO NOT want to place the switch for 10K outward for this PCM, both switches inward.
http://www.youtube.com/watch?v=GDzeSi5nmoo&list=PL0CA878598D87BA29

What does your CEL do when Key On Engine Off? Does it go off when engine is started?

Changing a 4.3L bin file to a 7.4L bin file is much more complicated then just changing displacement!!!

Hi EagleMark,
I did copy and paste many of the tables from the 7.4 to the 4.3 as well as changing the cyl count and displacement...It took me many hours you're so right

[dave w]

My thoughts are 100% based on personal experience.

I've learned the hard way to use an original 7.4 liter '7427 Memcal, that in itself was pain reliever for many headaches!

It was a royal pain in the !#@, but I copied over the $OE 454 engine parameters into a $OD 4L60E .bin file.

Now that is TUNING!

dave w

[K1500ss4x4]

Whoops!

[K1500ss4x4]

My thoughts are 100% based on personal experience.

I've learned the hard way to use an original 7.4 liter '7427 Memcal, that in itself was pain reliever for many headaches!

It was a royal pain in the !#@, but I copied over the $OE 454 engine parameters into a $OD 4L60E .bin file.

Now that is TUNING!

dave w

If I do that doesn't it also change the hex addresses which will also change the wiring of the harness?

[brian617]

I would suggest V8 memcal at very least. Might be easier to convert BJYL (5.7L 4L60e .bin) to 7.4L than converting 4L80e to 4L60e.

Here is link for BBC IAC wiring

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1227-1227747-IAC-wiring-to-IAC-for-Big-Block-and-Small-Block

[EagleMark]

Hi EagleMark

Thanks for that Yes I did enter AA in the Mask ID and the switches are in the correct position inward. I went over the videos at Moates. The CEL stays on. I wish Dave would have been more thorough he's kind of short tempered.... He and Brian Harris from Harris performance both told me to use the 4.3 bin modified. I'm confused now should I have saved the harness from the c3500 HD?Well Dave at Moates is normally very friendly and helpful so not sure why he was having a bad day. He also usually just refers guys here with GM stuff.

Brian Harris at TBI Chips is really getting a bad reputation all over the internet and we end up fixing many of his so called custom tunes. Off the shelf fancy name stuff is just crap! Problem is most people don't have equipment or skills to tune and then they would not know a good running engine from bad! So he's gotten away with it for years...

You can make the engine run by just changing the bin file, but what about the knock module? What about LHM/netres? I know the knock won't work correctly. Pretty sure the Netres needs a jumper. I just don't mess with this and start with correct parts.

There's absolutely no reason to change the harness!

Another issue you may have not addressed is fuel pressure? 95 7.4L injectors are smaller then earlier ones and run much more pressure then 13 PSI... IIRC it's like 30 PSI. So in bin file the Injector constant would be wrong as well with wrong fuel pressure.

If your CEL stays on? What codes are set?

[K1500ss4x4]

My thoughts are 100% based on personal experience.

I've learned the hard way to use an original 7.4 liter '7427 Memcal, that in itself was pain reliever for many headaches!

It was a royal pain in the !#@, but I copied over the $OE 454 engine parameters into a $OD 4L60E .bin file.

Now that is TUNING!

dave w

Hi dave w

Did you post a copy of that BIN so I could download it?

[K1500ss4x4]

Well Dave at Moates is normally very friendly and helpful so not sure why he was having a bad day. He also usually just refers guys here with GM stuff.

Brian Harris at TBI Chips is really getting a bad reputation all over the internet and we end up fixing many of his so called custom tunes. Off the shelf fancy name stuff is just crap! Problem is most people don't have equipment or skills to tune and then they would not know a good running engine from bad! So he's gotten away with it for years...

You can make the engine run by just changing the bin file, but what about the knock module? What about LHM/netres? I know the knock won't work correctly. Pretty sure the Netres needs a jumper. I just don't mess with this and start with correct parts.

There's absolutely no reason to change the harness!

Another issue you may have not addressed is fuel pressure? 95 7.4L injectors are smaller then earlier ones and run much more pressure then 13 PSI... IIRC it's like 30 PSI. So in bin file the Injector constant would be wrong as well with wrong fuel pressure.

If your CEL stays on? What codes are set?

Hello EagleMark thanks for the reply!

Yes Dave has been cool he probably was having a bad day.

I changed the fuel pump to the one from the C3500 HD so that's OK I adjusted the lbs per hour to the value in the 7.4 bin.
By "correct parts" are you referring to the 7.4 memcal? it has 4l80E info in it. can I still use it with 4L60E?
I tried to get codes a few days ago but could not get them the CEL just stayed constant. I'm a newbie not even sure what LHM/netres is can you explain?

[K1500ss4x4]

I would suggest V8 memcal at very least. Might be easier to convert BJYL (5.7L 4L60e .bin) to 7.4L than converting 4L80e to 4L60e.

Here is link for BBC IAC wiring

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1227-1227747-IAC-wiring-to-IAC-for-Big-Block-and-Small-Block

Thanks brian
I'll check that out...That is for a 1227747 ECM is it the same?

[brian617]

Thanks brian
I'll check that out...That is for a 1227747 ECM is it the same?

I could be wrong, but I believe its the coils in the IAC motor that are wired differently and the ECM/PCM are same.

[K1500ss4x4]

I would suggest V8 memcal at very least. Might be easier to convert BJYL (5.7L 4L60e .bin) to 7.4L than converting 4L80e to 4L60e.

Here is link for BBC IAC wiring

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1227-1227747-IAC-wiring-to-IAC-for-Big-Block-and-Small-Block

That wiring is for a 1227747 ECM is it the same for all ECM/PCMS

[K1500ss4x4]

Yeah that's the problem I'm running into I'm never sure if it's wired correctly and until I'm sure, I can't be sure of anything! BUMMER.

[brian617]

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-OD

Post #11 wiring diagram for 427

[JeepsAndGuns]

By "correct parts" are you referring to the 7.4 memcal? it has 4l80E info in it. can I still use it with 4L60E?

Yes or no, do you have the 7.4 memcal?

If yes, use it! You said you are using the G1 adapter right? Remove the 4.3 memcal and install the 7.4 memcal. All the transmission controlls are in the BIN file, the knock module and limp home chips in the memcal have no effect on the trans.

I also suggest ditching the 4.3 bin completely and use a 5.7 bin of the same year as your trans. There are so many differences in a V6 bin and V8 bin, I personally would not use one to run the other.

[EagleMark]

Why are you so worried about wiring when it's a stock harness? The only issue may be IAC and you won't even know until you get it to run without a CEL and have idle issues!

You'll have to get this thing running right to see if you have IAC/Idle issues first. Then because of the SB to BB the first thing to look at is IAC wiring. I'm just not sure if the newer stuff is swapped like the older stuff?

Limp Home Chip or Netres chip is an extra chip in older ECM and it's in the Memcal on newer PCM. In catastrophic failure it keeps the engine running safely, not good but safely. There's also some differences in how the PCM handles fueling when running correctly. Many of the old camaros Memcals were sucked up over the years in TPI trnasplant engines and they are scarce, so the guys at ThirdGen.org figured out how to make a V6 Memcal work V8 fueling with a jumper wire.

But there's no shortage of V8 Memcals for this PCM, so why go that route and still have the wrong Knock Module?

I'm really not sure how the V6 Memcal Netres in 16197427 and similar PCM effects fueling? Just never tried as there's plenty of correct parts.

Does someone know for sure this V6 Memcal will mess up V8 fueling?

[dave w]

I don't know if a V6 memcal will mess up V8 fueling. I find it very interesting my Auto Xray AX7000 Scan Tool knows when a '7427 PCM has a 4.3 vs. 5.7 vs. 7.4 liter memcal installed.

I firmly believe, the best solution is to install an original 7.4 liter memcal and copy / paste the 7.4 liter engine parameters into a $OD 4L60E .bin file. I'm thinking 1995 would be a PWM TCC .bin file. I know this is a cumbersome chore! I had two instances of TunerPro open when I did it. I'm very willing to freely provide an answer, but I don't do homework for others for free.

dave w

[K1500ss4x4]

Yes or no, do you have the 7.4 memcal?

If yes, use it! You said you are using the G1 adapter right? Remove the 4.3 memcal and install the 7.4 memcal. All the transmission controlls are in the BIN file, the knock module and limp home chips in the memcal have no effect on the trans.

I also suggest ditching the 4.3 bin completely and use a 5.7 bin of the same year as your trans. There are so many differences in a V6 bin and V8 bin, I personally would not use one to run the other.

Thanks everyone for all your help!!!!

Yes JeepsandGuns I do have the chip for the 7.4 I was told NOT to use it because of the mask differences $31 and transmission differences. But I guess I'll try it like you say Remove the G1 take off the $OD 4.3/4l60E chip and replace with the $31 7.4/4l80E chip and it will not damage my transmission or have wiring problems?
Sorry to ask again but I have to be sure as you know, the transmission was not cheap.

[K1500ss4x4]

I don't know if a V6 memcal will mess up V8 fueling. I find it very interesting my Auto Xray AX7000 Scan Tool knows when a '7427 PCM has a 4.3 vs. 5.7 vs. 7.4 liter memcal installed.

I firmly believe, the best solution is to install an original 7.4 liter memcal and copy / paste the 7.4 liter engine parameters into a $OD 4L60E .bin file. I'm thinking 1995 would be a PWM TCC .bin file. I know this is a cumbersome chore! I had two instances of TunerPro open when I did it. I'm very willing to freely provide an answer, but I don't do homework for others for free.

dave w

I did that with the 4.3 BIN file, side by side copied and pasted tables and such from one to the other it took me about 4 tries before I felt it was good and many hours of homework. The only thing I haven't done is install the 7.4 memcal I've been using the 4.3 one This is the first time I've heard this solution. I'm surprised because I THOUGHT that the 7.4 used a different mask and would not be compatible with the OD harness/PCN etc?

[EagleMark]

Install the 7.4L memcal with your G1 adapter and chip. You've already done the work to the bin file with correct year 4L60E trans and copied all the 7.4L engine parameters.

The PCM for $31 and $0D are the same, we swap to $0D on them all the time.

Disconnect batt to clear codes and tell us what CEL does at key on? Does it go off when started? Look in your ADX file for what codes are set.

[EagleMark]

I do have the chip for the 7.4 I was told NOT to use it because of the mask differences $31 and transmission differences.You were told wrong because you are replacing the chip/bin file with one that is correct.

[EagleMark]

I THOUGHT that the 7.4 used a different mask and would not be compatible with the OD harness/PCN etc?You almost THOUGHT correctly, but you changes the chip/bin/mask to the correct one. All you need now is correct Memcal!

[K1500ss4x4]

Why are you so worried about wiring when it's a stock harness? The only issue may be IAC and you won't even know until you get it to run without a CEL and have idle issues!

You'll have to get this thing running right to see if you have IAC/Idle issues first. Then because of the SB to BB the first thing to look at is IAC wiring. I'm just not sure if the newer stuff is swapped like the older stuff?

Limp Home Chip or Netres chip is an extra chip in older ECM and it's in the Memcal on newer PCM. In catastrophic failure it keeps the engine running safely, not good but safely. There's also some differences in how the PCM handles fueling when running correctly. Many of the old camaros Memcals were sucked up over the years in TPI trnasplant engines and they are scarce, so the guys at ThirdGen.org figured out how to make a V6 Memcal work V8 fueling with a jumper wire.

But there's no shortage of V8 Memcals for this PCM, so why go that route and still have the wrong Knock Module?

I'm really not sure how the V6 Memcal Netres in 16197427 and similar PCM effects fueling? Just never tried as there's plenty of correct parts.

Does someone know for sure this V6 Memcal will mess up V8 fueling?

Hi EagleMark,
Does the LHM use the same mask or is that section of the memcal on a separate system? I'm going to use the 7.4 memcal in my G1 adapter and try one of the bin files I modified from a 5.7 to work with my 7.4 does that sound about right?

YOU GUYS ARE AWESOME!!!!! OH BOY YOU ALREADY ANSWERED MY QUESTION i DIDN'T SEE IT UNTIL AFTER i POSTED SORRY!

[K1500ss4x4]

Hey guys,

Thanks again for all your ideas. I'll let you know how this works. Goodnight.

[K1500ss4x4]

Hey Guys!!!!

Great news She's running great, idle good, data streaming with 7.4 memcal in G1 still have CEL I believe I ran a datalog can I post it somewhere to have someone look at it and decipher it for me?

[EagleMark]

It's about time! :laugh:

When you click the reply, look at bottom of box for Go Advanced. Then at bottom of that you will see attachment manager and can attach the TunerPro .xdl file you recorded.

[K1500ss4x4]

Thanks EagleMark I uploaded 2 files 1 at idle mostly the onter with some rpms I know I need a knock sensor and will get it tonight 1 question the v6 has 2 knock sensorsI believe in series the 7.4 only uses 1 this should function ok right? ( the harness has 2 knock sensor plugs on it.

Thanks Bobby

[Woods]

1 question the v6 has 2 knock sensorsI believe in series the 7.4 only uses 1 this should function ok right? ( the harness has 2 knock sensor plugs on it.

Thanks Bobby

Ran into that on my swap also. Just use one sensor. Tape up, or do away with the other connector on the harness.

[K1500ss4x4]

Well, I road tested her today and it does shift, but when you get on it, the transmission flares and the engine goes way beyond redline, pegs the tach needle any other ideas out there?

Could this be due to the 4L80E memcal?

[K1500ss4x4]

Ran into that on my swap also. Just use one sensor. Tape up, or do away with the other connector on the harness.

Thanks for that Woods, I was kinda thinking in that direction.:yikes:

[dave w]

Well, I road tested her today and it does shift, but when you get on it, the transmission flares and the engine goes way beyond redline, pegs the tach needle any other ideas out there?

Could this be due to the 4L80E memcal?

I don't think the 4L80E Memcal is the issue. I'm using a 4L80E Memcal for the 7.4 / 4L60E conversion I did.

dave w

[EagleMark]

There's nothing in the Memcal that effects transmission except the chip/bin file!

Or an issue with the trans? Did you say it's new? Does not mean it's correct...

[K1500ss4x4]

There's nothing in the Memcal that effects transmission except the chip/bin file!

Or an issue with the trans? Did you say it's new? Does not mean it's correct...

It's about 1 yr old bought it knowing I was going to do this transplant worked fine with the v6. The rev limiter didn't work either.

[EagleMark]

Thanks EagleMark I uploaded 2 files 1 at idle mostly the onter with some rpms I know I need a knock sensor and will get it tonight 1 question the v6 has 2 knock sensorsI believe in series the 7.4 only uses 1 this should function ok right? ( the harness has 2 knock sensor plugs on it.

Thanks BobbyI looked at the second file and all looks pretty darn good!

Except for a constant 4* of knock retard and we know why... the knock error is also set.

TIP: When you do a log for tuning start with engine at total warm up! It was still climbing when the log ended.

[Fast355]

Well, I road tested her today and it does shift, but when you get on it, the transmission flares and the engine goes way beyond redline, pegs the tach needle any other ideas out there?

Could this be due to the 4L80E memcal?

Is it flaring during the 1-2 shift or is it slipping while driving. I could not keep a 700r4/4L60E together behind a mild 350, much less a 454. Just personal experience here. At the minimum I would make for sure it has an 093 servo in it and check the line pressure with the transmission connector unplugged. I like 230-240 psi of line pressure with the case connector unplugged at 2,000 rpm.

As long as you are running a $0D based .bin and its not in LHM its not the memcal causing your issue.

You are probably needing to remap the line pressure tables much more aggressively than stock. Also you may end up needing to start the shift at a lower rpm than a stock 350. Might also have to reduce the timing in the cell closest to the RPM you shift at at WOT to kill some torque. What I mean by that is if you are shifting at say 4,400 rpm, you would make you 4,800+ RPM timing cells substantially lower than your 4,000 rpm cell to cause the timing to retard right as the rpm hits the shift point. I have alot of experience trying to bandaid a 4L60E in a high torque, heavy vehicle application.

[K1500ss4x4]

Helllo There!

Guess what the flare was? The rear tires breaking loose! I can't keep traction when I get on it! This thing is a beast I'm going to have to get grippier tires!

[K1500ss4x4]

Is it flaring during the 1-2 shift or is it slipping while driving. I could not keep a 700r4/4L60E together behind a mild 350, much less a 454. Just personal experience here. At the minimum I would make for sure it has an 093 servo in it and check the line pressure with the transmission connector unplugged. I like 230-240 psi of line pressure with the case connector unplugged at 2,000 rpm.

As long as you are running a $0D based .bin and its not in LHM its not the memcal causing your issue.

You are probably needing to remap the line pressure tables much more aggressively than stock. Also you may end up needing to start the shift at a lower rpm than a stock 350. Might also have to reduce the timing in the cell closest to the RPM you shift at at WOT to kill some torque. What I mean by that is if you are shifting at say 4,400 rpm, you would make you 4,800+ RPM timing cells substantially lower than your 4,000 rpm cell to cause the timing to retard right as the rpm hits the shift point. I have alot of experience trying to bandaid a 4L60E in a high torque, heavy vehicle application.
Hi Fast355 thanks for the reply!

This had a 4.3Lv6 not a 350 v8 in it
Guess what the flare was? The rear tires breaking loose! I can't keep traction when I get on it! This thing is a beast I'm going to have to get grippier tires!

I think you're right about the shift points I need to change them how would I go about doing that?

[K1500ss4x4]

Hello everyone!

A quick update on the 454ss4x4 project. I've been driving it for a few days now and it's doing really well brought to a trans shop to double check after he took it out for a test drive the guy said "Man this truck is sweet" The one thing I came upon while browsing sites was the year of the bin files might matter the bin I used was for a 1994 4l60e but I have a 1995 will that make a difference?

[EagleMark]

The one thing I came upon while browsing sites was the year of the bin files might matter the bin I used was for a 1994 4l60e but I have a 1995 will that make a difference?Read man read! Post 6 on first page of this thread!

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2815-K1500-4-3-to-7-4-swap&p=34977&viewfull=1#post34977

[K1500ss4x4]

Read man read! Post 6 on first page of this thread!

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2815-K1500-4-3-to-7-4-swap&p=34977&viewfull=1#post34977

OK OK I deserved that! so where can I find a bin file for a 1995 4l60e that I can add my own 7.4 files to?

[EagleMark]

Read man read! :laugh:

Post 21 of this thread you started!

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2815-K1500-4-3-to-7-4-swap&p=34996&viewfull=1#post34996

The change between 94 and 95 is the TCC changed to a PWM version which had much heavier Kevlar IIRC clutches for more slippage and smoother operation and of course programming in the PCM bin file.

[K1500ss4x4]

Read man read! :laugh:

Post 21 of this thread you started!

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2815-K1500-4-3-to-7-4-swap&p=34996&viewfull=1#post34996


The change between 94 and 95 is the TCC changed to a PWM version which had much heavier Kevlar IIRC clutches for more slippage and smoother operation and of course programming in the PCM bin file.


Hey EagleMark

How do I find out the rear/front ratio of a bin file if it isn't in the description? my truck has 3.73 gear ratios

After several hours of combing through my current 1994 bin file I came upon this "TCC PWM 1995 Only" and checked the SET box so now I won't need to rewrite my bin to accomodate my 1995 4L60E right?

[EagleMark]

Gear ratios in descriptions are just notes someone has added in. There's nothing in this particular PCM that has anything to do with axle ratios. I've found very little to no difference in how the tune is changed because of axle ratios... so don't worry...

[K1500ss4x4]

Gear ratios in descriptions are just notes someone has added in. There's nothing in this particular PCM that has anything to do with axle ratios. I've found very little to no difference in how the tune is changed because of axle ratios... so don't worry...

Cool thanks for that I was worried about using the wrong ratio.

Well i"ve used the idle tables to really bring down the idle in park I'm at 700 in D I'm at 600 awesome!!

Now how do I get my Tach in the dash to read the same as the tach in TunerPro? it's about 500 rpm to fast since i switched from v6 to v8.

[EagleMark]

Now how do I get my Tach in the dash to read the same as the tach in TunerPro? it's about 500 rpm to fast since i switched from v6 to v8.

:confused:

The signal to tach comes from wire off coil. So now that it is running correctly I would suspect it to be correct... but maybe there is a differnce in the tach?

[K1500ss4x4]

:confused:

The signal to tach comes from wire off coil. So now that it is running correctly I would suspect it to be correct... but maybe there is a differnce in the tach?

Yeah it might be a electro-mechanical thing (like a resistor change) because the tach is definitely still off by at least 500 rpm the redline goes OVER 5000 rpm and the shift points don't seem right unless I'm completely nursing it and when TunerPro says I'm at 600 rpm my tach says more like 1100 rpm

[K1500ss4x4]

Oh no! another question!!!

I put in a 180 deg thermostat stock is 195 deg I don't want it running that hot are there any changes I'll need to make in the software to compensate?

[JeepsAndGuns]

All the aftermarket tachs I have seen have a switch on the back for 4, 6, or 8 cyl engines. They simply count the number of times the coil discharges in a set ammount of time and use that to display rpm.
Not knowing how the factory chevy tach is set up, I do not know if the curent one could be modded to work, or if it would need swapped out for a V8 one. I'm sure a little google searching could find you the answer.

[brian617]

Now how do I get my Tach in the dash to read the same as the tach in TunerPro? it's about 500 rpm to fast since i switched from v6 to v8.

You'll need to change the instrument cluster to one out of a V8 truck.

[Woods]

Now how do I get my Tach in the dash to read the same as the tach in TunerPro? it's about 500 rpm to fast since i switched from v6 to v8.

Dakota Digital
SGI-8 Tachometer Interface
http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=127/category_id=287/home_id=59/mode=prod/prd127.htm

Do-it yourself articles, the problem is, different years use different capacitor values.

http://www.s10forum.com/forum/f62/how-to-disassemble-and-calibrate-your-94-97-cluster-pic-heavy-481326/

http://www.chevytalk.org/fusionbb/printpost.php?tid/56905/