racprops
OBS Enthusiast
I THOUGHT I had this all laid out.
I have spent the past 3 years building a low RPM 383 for a high MPG engine for my 93 G20 Custom van, and plan on running a Motorhome 4L80e with a US Gear Dual range over drive to a stock 3.42 rear end.
AND That I could convert the two 8625s PCMs I have on hand as per the instructions in the doc.: Converting a V8 engine from TBI to MPFI using the 8625, 6395 or 7427 PCM, using the $E6, $0D, or $0E mask.
3 years ago I HAD found a tuner that said he could program a 8625 to operate a 4L80e with a eprom change, or some other reprogramming and he could also include a lean burn program such as the one in the Camaro PCMs.
Sadly I cannot reach him or find him. The virus delayed my work nearly the full three years. I lost track of some of the data.
I am trying to retrace my steps but not having much luck.
I found a tuner who does MPG tuning (VERY rare) but he is not the one, and saids:
“I believe I understood you correctly. I am saying that the 4L80E requires different solenoid activation than does the 4L60E. Not sure if these older ECMs have the ability to modify that or not (the LT1 PCMs do). That's what I'm checking with TunerCat about. I will check out the van calibration and see if the highway mode is available in it too (haven't worked with that one before).”
“Just heard back from him:
LT1 PCM Tuning
"No, as far as I know this PCM was never used with a 4L80E transmission. This would be a $E6 calibration. The 1993 heavy duty trucks that had the 4L80E transmission used the 16147060/16127470 PCM which is an $85 calibration."
” So it sounds like if you want to use your 4L80E then you'll need to use that '93 PCM that he references above, with the $85 definition file. I'm willing to help you tune that (via email) if you want/need it.”
So at this point I am totally lost, Looking at: https://www.thirdgen.org/forums/tbi/442325-notes-information-converting-tbi.html
And: TBI guys, its time to update! - Third Generation F-Body Message Boards with its 483 posts I am totally unable to comprehend it.
At this very hour I am leaning back to the idea of running one of the original TPI MAF PCM to run the fuel injection and running a 93 G30 PCM piggy backed to operate the 4L80e transmission.
So I am asking for a simple path to get this van running at its best, I am looking for a G20 Van getting from 20 to 30MPG.
I have the engine made to make torque from 1500RPMs, so it should pull easily, no lugging, I have the stock TPI system to feed it and with highway mode run lean for MPG, and I have the drive line gearing to run her at 1800RPMs at 80MPH.
Please help me get all of this together.
So I can find 16147060/16127470 PCM, and ones running 4L80e's but now I need instructions of converting them to run 8 injectors MPFI....
At this very hour I am leaning back to the idea of running one of the original TPI MAF PCM to run the fuel injection OR making the mods to my 8625s and running a 93 G30 4L80e PCM PCM piggy backed to operate the 4L80e transmission.
Thanks for your time.
Rich
racprops on third gen, (and here) which I discovered back in the mid 90s…when they discovered the Lean burn Setting…and that Camaros down under got 30/35MPG.
I have spent the past 3 years building a low RPM 383 for a high MPG engine for my 93 G20 Custom van, and plan on running a Motorhome 4L80e with a US Gear Dual range over drive to a stock 3.42 rear end.
AND That I could convert the two 8625s PCMs I have on hand as per the instructions in the doc.: Converting a V8 engine from TBI to MPFI using the 8625, 6395 or 7427 PCM, using the $E6, $0D, or $0E mask.
3 years ago I HAD found a tuner that said he could program a 8625 to operate a 4L80e with a eprom change, or some other reprogramming and he could also include a lean burn program such as the one in the Camaro PCMs.
Sadly I cannot reach him or find him. The virus delayed my work nearly the full three years. I lost track of some of the data.
I am trying to retrace my steps but not having much luck.
I found a tuner who does MPG tuning (VERY rare) but he is not the one, and saids:
“I believe I understood you correctly. I am saying that the 4L80E requires different solenoid activation than does the 4L60E. Not sure if these older ECMs have the ability to modify that or not (the LT1 PCMs do). That's what I'm checking with TunerCat about. I will check out the van calibration and see if the highway mode is available in it too (haven't worked with that one before).”
“Just heard back from him:
LT1 PCM Tuning
"No, as far as I know this PCM was never used with a 4L80E transmission. This would be a $E6 calibration. The 1993 heavy duty trucks that had the 4L80E transmission used the 16147060/16127470 PCM which is an $85 calibration."
” So it sounds like if you want to use your 4L80E then you'll need to use that '93 PCM that he references above, with the $85 definition file. I'm willing to help you tune that (via email) if you want/need it.”
So at this point I am totally lost, Looking at: https://www.thirdgen.org/forums/tbi/442325-notes-information-converting-tbi.html
And: TBI guys, its time to update! - Third Generation F-Body Message Boards with its 483 posts I am totally unable to comprehend it.
At this very hour I am leaning back to the idea of running one of the original TPI MAF PCM to run the fuel injection and running a 93 G30 PCM piggy backed to operate the 4L80e transmission.
So I am asking for a simple path to get this van running at its best, I am looking for a G20 Van getting from 20 to 30MPG.
I have the engine made to make torque from 1500RPMs, so it should pull easily, no lugging, I have the stock TPI system to feed it and with highway mode run lean for MPG, and I have the drive line gearing to run her at 1800RPMs at 80MPH.
Please help me get all of this together.
So I can find 16147060/16127470 PCM, and ones running 4L80e's but now I need instructions of converting them to run 8 injectors MPFI....
At this very hour I am leaning back to the idea of running one of the original TPI MAF PCM to run the fuel injection OR making the mods to my 8625s and running a 93 G30 4L80e PCM PCM piggy backed to operate the 4L80e transmission.
Thanks for your time.
Rich
racprops on third gen, (and here) which I discovered back in the mid 90s…when they discovered the Lean burn Setting…and that Camaros down under got 30/35MPG.