I have an LT4 which has the 27.4 lbs injectors rated at 43 psi. I got a set of 28.8 lbs LS6 injectors which are rated at 58.4 psi. I can run the LS6 28.8 lbs injectors running at 53 PSI to get me 27.44 lbs.

Do I need to get a PCM reprogram for this anyway?

 

I waited to see if anyone would answer earlier over on the scan & tune as I'm also interested in others opinions, as you know I run that setup at 58.4 psi for the full 28.8 Lb/hour.

I initially had Brian at PCMFORLESS setup my PCM for the above & yes he did need to reprogram, I know LT1 Edit, uses fuel pressure in one of the programming macros for fuel trim.

But I think since it (LT1 Edit) is setup for the LT series engines Std fuel pressure @ 43.5, it uses that macro to calculate the deviation between 43.5 psi & say 58.4 psi. It then calculates the actual LT series Inj Lb/hour at 58.4 which would come out to 30 Lb/hour something.

But since it is an LT series fuel/PCM program I think it (program macro) does not know our LS series Inj's are rated 28.8 Lb/hour @ 58 PSI.

This is just my recent theory, I THINK its pretty close though.
.
To sum it up I think we need to set the actual fuel pressure with the regulator where we want to run it 53/58 psi then when programming with LT1 Edit put in the calculated Inj size, in your case 27.44, and then put 43.5 (Std) in the fuel pressure macro as if you put the 53.4 in the program it will think your 27.44 is larger than 27.44.

I'd also like to hear other opinions, were not the first to do this Brian @ PCMFORLESS told me he had done quite a few recently, but he's not real open to disclosing what he does to set them up.

Whatever he did it was very close as my Datamaster scans had o2 sensor reading's in the high 800's which is supposed to be optimum for LT engines, and my BLM's hovered around 128 which is perfect.

I would sure welcome anyone that has worked with these parameters in LT1 Edit to jump in and present their theories.


:cheers:


[Modified by superlund, 11:46 PM 12/22/2002]

 

I just got an email from Bryan at PCMforless and he said that I would be fine adjusting the psi on the adjustable fuel pressure regulator. No re-program needed. :)

 

I know in another post you had a PCMFORLESS program running in your PCM, but you were thinking about swapping a stock one back in.
Which PCM did you end up with?

 

I have an Ed Wright and a PCMforless. I was going to flash the PCMforless one to stock because you can't with the Ed Wright PCM. I decided against that idea. I currently run the Ed Wright PCM. I was getting a few DTCs with the PCMforless and have not bothered to ship it back. I was really waiting to get my problems addressed first.