1227747 to 16197427 Conversion Box!

[d0nk3y]

No, dont make that adapter, its a royal pain in the butt to make. Trust me, I made one. Once you plug the 7427 in and run it, you wont want to go back to the 7747. I made that adapter, plugged it in and took a test drive. I never plugged the 7747 back in. I removed the adapter and removed the pins from the 7747 connectors and put them in the 7427 connectors and never looked back. Took probably 4 times as long to make the adapter than it did to re pin the connectors.

I'm going to use the 7427 for my own projects.
I'm just going to make the adapter to get faster data acquisition in vehicles setup with 7747 ecus. Seems I know lots of people with modified TBI engines that don't quite run right. When I go trash-pickin at the local JY, I don't want to have to always be on the lookout for a 7427 for a "Buddy", lol! I'm having a helluva time tuning this latest truck; it's a "mystery" 350 with a huge cam and a stock stall speed converter. Guy bought it from someone else and got tired of it flooding out on hills (offroading), so he paid $$$ for a TBI harness and put a TBI and manifold on it then wondered why it wouldn't run. That dang 747 gives me a lil bit of data every 1.2 seconds, whether I need it or not ;) and it's just not fast enough to catch the transients.

Anywhoo, I liberated connectors from a 747 box today and I'm just siting down to make up my excel sheet for listing the circuits & location for each ECU. After that, just some swapping of wires, lol.

[dave w]

Try using the attached Excel spreadsheet for fixing VE tables. The spreadsheet includes the older '7747 and the newer TBI PCM with $OE, $E6, $OD, $31. Copy / Paste the running averages from the TunerPro RT BLM History Tables. Compared to other VE Fixers, the attached spreadsheet is simple to use and will get the VE about 90% ~ 95% accurate.

dave w

[EagleMark]

I'm going to use the 7427 for my own projects.
I'm just going to make the adapter to get faster data acquisition in vehicles setup with 7747 ecus. Seems I know lots of people with modified TBI engines that don't quite run right. When I go trash-pickin at the local JY, I don't want to have to always be on the lookout for a 7427 for a "Buddy", lol! I'm having a helluva time tuning this latest truck; it's a "mystery" 350 with a huge cam and a stock stall speed converter. Guy bought it from someone else and got tired of it flooding out on hills (offroading), so he paid $$$ for a TBI harness and put a TBI and manifold on it then wondered why it wouldn't run. That dang 747 gives me a lil bit of data every 1.2 seconds, whether I need it or not ;) and it's just not fast enough to catch the transients.

Anywhoo, I liberated connectors from a 747 box today and I'm just siting down to make up my excel sheet for listing the circuits & location for each ECU. After that, just some swapping of wires, lol.

So you will have an adapter to plug into a 7747 and use a 97427 to record data to tune with? That sounds like a cool idea. Here's a link with the pin by pin change needed:
http://www.gearhead-efi.com/Fuel-Inj...light=16197427

[d0nk3y]

Dave W - thank you! I'll check that out!

EagleMark - You just gave me exactly what I was going to construct in excel: Thank you very much!

~Scot

[EagleMark]

I thought that was what you were up too! No need to re-invent the wheel. You'll find we all work and learn well from each other here!

[d0nk3y]

Have things wired up per the pinouts and not seeing enough over serial data line; i.e. RPM would be nice. Just went though and repinned the harness and checked for shorts and missing wires when I find:

I would also like to mention that the orange Serial Data wire needs to be
relocated from the top row, Pin "E" to the lower row, Pin "M". You will also
need to scan the vehicle like a 1993-1995 G-Series Van, C-Series Truck,
S-Series Blazer, etc with Auto transmission.

So, I wired in a separate ALDL into my translation harness - figure if TunerPro is using a 16197427 adx, the serial line should be in the right spot. I just need to go back out and check out some voltages, but it's too dang cold and dark outside. :D




How's that for STEALTH?

[dave w]

I've recently learned, that the 700R4 TCC control wire is Pin E11 NOT E10!!

dave w

[EagleMark]

Pretty sweet setup for the purpose. Let us know how it turns out when you get 427 data and redo the 7747 bin.

[d0nk3y]

Thanks!
I also spent a few hours measuring the cam profile on the engine I'm working on; looks to be fairly close to a comp cams 260H with around a 105 degree LSA. That helps explain the "fun" I've been having with the VEs at idle, LOL! He may just end up with a 7427 in this thing after all is said and done; looking through the code, there's some great stuff in there this motor could take advantage of.

I know, I know - wasn't someone here telling me to forget the 7747 and just use the 7427 and be done with it?

Scot

P.S. Here's a shot of the beast I'm working on; I moved the step-ladder out of the way to take this.

[JeepsAndGuns]

"I would also like to mention that the orange Serial Data wire needs to be
relocated from the top row, Pin "E" to the lower row, Pin "M". You will also
need to scan the vehicle like a 1993-1995 G-Series Van, C-Series Truck,
S-Series Blazer, etc with Auto transmission. "

I have read this a couple times myself, but first time I read it was after I had already been datalogging with my 7427.
I have never moved the pins in the ALDL plug and it still works just fine. But I have read where other people have had to swap because they couldnt get aldl connection. Why would mine still be working just fine?

[d0nk3y]

Good question! I have also found some info on another website that claims it is hit-or-miss with changing the Serial data line.

Hey- I was getting ready to contact you - did you get the money I sent for the 7427? I may need it for this vehicle.

[EagleMark]

Thanks!
I also spent a few hours measuring the cam profile on the engine I'm working on; looks to be fairly close to a comp cams 260H with around a 105 degree LSA. That helps explain the "fun" I've been having with the VEs at idle, LOL! He may just end up with a 7427 in this thing after all is said and done; looking through the code, there's some great stuff in there this motor could take advantage of.

I know, I know - wasn't someone here telling me to forget the 7747 and just use the 7427 and be done with it?

Scot

Another way to see how much trouble you will have tuning a big cam is the old fashion vacuum gauge!

I did a HUGE truck like yours but he had a cam so big it never had any power at low RPM and he could not Rock Crawl, was great at mud bogs... so I changed the cam first (went from 9 to 13 at idle) and he liked it a lot more, then did an EFI conversion tuning.

[EagleMark]

"I would also like to mention that the orange Serial Data wire needs to be
relocated from the top row, Pin "E" to the lower row, Pin "M". You will also
need to scan the vehicle like a 1993-1995 G-Series Van, C-Series Truck,
S-Series Blazer, etc with Auto transmission. "

I have read this a couple times myself, but first time I read it was after I had already been datalogging with my 7427.
I have never moved the pins in the ALDL plug and it still works just fine. But I have read where other people have had to swap because they couldnt get aldl connection. Why would mine still be working just fine?

Well I figured out why!

First the pin out changes on the conversion from 1227747 to 16197427 are correct!
A8--------F9----------ORN------------Serial Datastream

But the difference is P3 1227747 puts out serial data at 160 baud speed to pin E.



The P4 16197427 puts out serial data at 8192 baud speed to in M.



The reason your getting data with your cable to computer on wrong ALDL port is:

Generally GM cars that use pin E are communicating at 160 baud speed, and the cars using pin M are communicating at 8192 baud. The pin locations are labeled inside of the 12 pin connector shell.
Pin M and pin E of our cables are jumpered together inside the connector shell and go to the same spot in the circuit. Again, you are only using one of these pins to read data, so only one of these pin locations will be populated on your vehicle. We jumper these 2 pins together so that this cable will work for any 1982 to 1995 era car, regardless of the pin layout in the car.

A scantool would not have 2 serial data connections jumpered together, it needs correct data on correct pin for each year/make/model car. You'll notice there are many other wires to the ALDL port for many other reasons depending on application used by scan tools. Things like ABS, TCM, BCM, SIR to name a few...

This may also be the reason some cars have so much trouble with TunerPro recieving serial data to ADS or ADX files, although we only ever use pin A which is a ground and pin B which is Diagnostic Link Test (DLC) for checking codes. And either pin E or pin M for serial data. Who knows what is on the other pin when the cable has two pins jumpered together? I know the ADS/ADX for 1990 1227730 corvette needs a silence command on it's serial data line because it is also tied into the Digatal Dash, but it would work without silence command on earlier models without digatal dash. I've still not got my $EE ADX to work on my Buick Roadmaster although it works on other LT1 engines and because this came up looked and sure enough I have another wire tied into my datastream?




So I need to find what that wire is and find the silence command for it.

[JeepsAndGuns]

Ahh, good info there mark! So that explains why it works just fine on mine without ever moving the pins. I guess I should swap that wire to the correct spot on the aldl plug just incase I am out somewhere and have to have a parts store scan it with a scan tool.


donkey, I never recieved any PM's or emails from you or paypal reguarding payment. I just assumed you no longer wanted the pcm. Send me a PM if you still want one and we can make sure there wasnt a typo by one of us on my email address.

[d0nk3y]

sending you a pm... :)