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 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-Inj...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=GDzeS...A878598D87BA29

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-Inj...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=GDzeS...A878598D87BA29

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-Inj...nd-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?