Had this posted in tuning section but wasnt getting a responce. Lets try it here where the boost addicts are.

Well Its been a great summer filled with work and some vacation but its time to bring my car out of the garage and start running her again. I didnt drive her too often in the summer due to the extreme hot temps in Miami and Ive been really busy with work. Ive been a member of LS1 Tech for years but I forgot my password and I have changed my email address so I cant login under BLMONGOOSE anymore.

Enough cathing up now its time to get technical.

After months of rest the car runs like crap. It turn on and the idle is very rough. When I turn on the A/C the engine shuts off on me and I have to keep gassing it up to prevent her from shutting off.

I decided to raise the idle from 900 to 1050 to see if that would fix my idle probelm. I got a new laptop so I dont have a serial port anymore, Iam using this Iconcepts USB-serial adapter. So I have gotten ls1-edit to work but it fails 3-15 times b4 it can link to the PCM and re-flash it. The EFI LIVE works good and I havent gotten Autotap to work properly (it works with engine off but the seccond I start the engine the thing looses connection and cant be re-established)

Flashed PCM with higher idle and car runs great now she just feels like she ready to run all the time.

I connected the EFI Live and the AFR is at 14.6:1 and my LTRIMS at idle are about +11.5 and +11.7 under moderate accelaration and cruising they are about -4.5 and -4.

This doesnt seem right to me, I cant remember but shouldnt my AFR be around 12.4:1. At 14.6:1 iam running very lean right?

I know the Ltrims should be running at negative 11-12 at cruising speed with the car in gear. but they are at -4.5 an -4 indicating the car is running rich right?

Iam confused. I need some advise to jog my memory again? what going on with my car and these readings.

I also forgot how to convert my map pressure gm/s to gms/cyl so that I can see where on my timing curve Iam at, in ls1 edit. I tried just dividing my gm/s by 8 cylinders but that gives me numbers in the 20's and 40's. In ls1 edit the number are all below 1.0 example .6 .48 .08?

In ls1 edit in the high octane table .6 gms/cyl would be about 60% throttle?

My car modifications: stock lower end, GWP ported heads and cam for blower, GWP-ATI #9 blower, headers, full exhaust, Front mounted intercooler and too many little boltons to mention.

 

At idle the AFR should be 14.7:1 (but if you are reading the AFR from efilive its only the commanded). Since your ltrims are +11 you are running pretty lean at idle but the pcm is adjusting. You want around 0 at idle. At what you want 12 to 13:1 AFR. I would not worry to much about -4 at WOT especially if you do not have a wideband o2 sensors. Gms/cly is a load and does not go off the map sensor. It is calculated by maf (gms/s) *15/rpm, its not directly related to throttle position.

Hope that helps some.

Gary

 

Ok, after running the car a few days, putting in some xylene in the old gas to clean out the injector and to boost the octane of the old gas. The car ran better. And with a new full tank of gas I put in this mourning shes running great agian.

Iam going to do another EFIlive log after the full tank of new gas to see where my AF ratio and Ltrims are at.

Red your right, its not the MAP it is the MAF, my mistake. But How do I convert my 320 gm/s reading in EFIlive to a number I can read in the high octane spark curve in ls1 edit. You mentioned something about 15 RPM do I have to divide by 15. Ex 320/(8*15)= 2.66gms/cyl???

I want to figure this out so i can see where my timing curve is at under a particular speed, RPM, or load.

 

TTT. Anyone know the conversion of translating gm/s to gms/cyl? I've tried a search and other sites but I havent found anything? I know that their is a formula I just dont remember it. Its been awhile.

 

There is a divide in that equation so gms/cly= maf(gms/s) * 15 / rpm.

Gary