K1500 4.3 to 7.4 swap

[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-Inj...nd-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-Inj...nd-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-Inj...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!