unable to get ls2 e40 to start when cold

i have been trying for about week to get my friends cammed gto to start when it cold. i have the tuning school manual which i find i like less and less the more learn. i have tried taking startup airflow to stock and going up 5 percent at a time until it was undoubtedly too high. tried going the other way did the same with cranking fuel. also tried tweaking the cranking ve table. the car starts for a second then the injector pulse goes high and it dies. i have also tried taking the maf low values and tables in ve down to try and correct and am having no luck. thank in advance for any and all help. i am aware the tune is not complete. just felt the startup and idle should be one of the first things done. the car has k and n intake. tick cam (231/[email protected] 111lsa lift is around .610) ported cylinder heads, pace setter long tube headers, 3inch collectors all the way back.

That tune needs help, no offense, but there are some inconsistincies in critical areas. Ill send you a PM.

start from stock and increase raf

Open Loop back to stock in area for cold start, also change PE Enable MAP to 15 & RPM Hyst to 30 rpm.

Tq mgmt >etc tps max > set the first column back to 0

fuel > general > injection timing - set these tables back to stock, no need to touch them on a cam only car.

in the spark over speed / underspeed , I never touch those tables unless someone is looking for alittle more chop from a small cam.

Try these changes for your cold start issue. Copy and Paste from the excel file to you posted tune.

Cam is pretty big. Based on overlap could give the injection timing a "tweak" to prevent fuel "short circuiting" between intake and exhaust valve opening. Also you may need to adjust the over/underspeed spark with a cam. The stock values are too aggressive for a radical cam and what happens is the natural lope of the cam generates rpm errors and the stock table will "fight" this and cause adaptive idle instability. The idea is to lessen the correction and let the cam lope handle itself and only intervene at say +-80 rpm error and up in a gentle approach.

Ed M

i had to get my truck back from him yesterday and give his car back to do some stuff around the house. i will mess with it more next weekend when i see him again. here is the tune that is in it now. i was reading one of greg banishe's books friday night and realized that the way i calculated the injection timing the first time may not have been ideal since the factory calibration injects fuel on closed valve and i had it set to inject after exh valve closed. i changed it so that it would have a little extra time when cold starting and tapered it off to get rid of the fuel smell and bucking when warm(helped a ton when i changed initially). i also changed the under and overspeed tables back to stock and the car actually started quite well the 10 or 12 times i got to try it but it warmed up here too so no cold start testing. he also has toldme that he likes the way it idles with more under and overspeed and was a little disappointed when i took it out initially to tame it down some so hopefully i can make it work with where it is now. thanks for the advise i will keep posted when i get a chance to do more.