Cold Startup Issues

[Camaro SS]

Cold starts are killing me. On a cold start I have to start the car about 3 times before it will stay running and the IAC counts are pegged at 310 and stay there. After the third start the car will surge alittle and then settle in to a nice idle. The IAC counts continue to stay at 310. I have LTIT disabled and it takes awhile before the STIT start reading. I have logged IAC - Start-up Airflow and at startup the scanner says the engine wants 16.6 grams/s more and I logged IAC - Start-up Friction Airflow and the scanner says that is wants 6.73 grams/s more. I have added more to it and then the next cold start the scanner will say that is wants even more air for the Start-up airflow and Start-up friction airflow. It just seems no matter what I do nothing seems to help. I am running the car in Open Loop. I can send anyone the scan and tune if you would like to look at it.

Hopefully someone out there has a good idea for me to try.

[vetteboy2k]

I have had the same issues with cold start. Any tables to modify to fix this is greatly appreciated. Custom OS3

[dfe1]

Sounds like you have a lot of camshaft, and not enough throttle opening. If the IAC is pegged at 310, that means it's adding all the air it can and it's still not enough. Try adjusting the throttle stop screw so that more air flows past the throttle plate. That will reduce the amount of air that needs to go through the IAC. It may also be necessary to drill a hole in the throttle plate, or enlarge the one that's already there. When you get the air flow past the throttle in the correct range, IAC counts should drop into the 200s at cold start. Keep in mind that the procedure used on Corvettes is different because IAC is handled by the electronic throttle control. Also, you don't mention anything about the manifold and throttle body you're using. That may also be affecting cold start, and require other adjustments.

[Camaro SS]

I will try that. I added some fuel to the after start enrichment and now when I start it up it revs up to like 1800 rpms. Now the car is kinda warm so I really won't know until tomorrow morning if the cold start is any better. I would think for it to rev up to like 1800 rpms it is getting too much air now right?