duncan01

Ive been fighting this issue for a while now and Im running out of options. On the first cold start of the day. It starts like normal and rev's but when it goes to settle the idle it stalls. Second start will fire and run and lope a little till it warms up, then runs like a champ. If I pedal it on the first start it will stay running.

-Testing
In tank fuel pump is a new 190lph. Rail pressure is 39 psi vac line off. Base Idol is set at 650rpm. IAC is new and TPS is set at .94 volts. Vacuum is reading about 16" +or- 1" with cam lope. All sensors are new. Plug reading is about dead on for air fuel, but looks like it could use a little more timing by the burn mark, Im running 10 degrees. Still running stock 19lb injector with appropriate mass air. Will be upgrading to 24's very soon followed by a dyno tune.

The car runs great when its up to temp no stumbling or hesitation. Suggestions are greatly appreciated.

Duncan

duncan01

133 views and no one has a thought

Mike T

Bump the timing up a few degrees. That should bring your idle up a little. You'll probably have to run 92 octane to help stave off detonation. Have you done a base idle relearn?

duncan01

I havent done a base reset yet, I havent seen a need to since it idols good when its warm. Im a little affraid to pump up the timing till I get the 24lbs injectors in it, since Im bound to be near max duty cycle of the stock ones.

dawson1112

How long has the air cleaner been on the car? Maybe a new filter or clean the Maf. Possibly even have a leak in the air intake tube after the maf.

duncan01

checked all intake tubing changed rubber connecting pieces, cleaned mass air and filter. No change. stumped

dawson1112

does it crank for what seems to be a longer time at first start of the day than normal??

Possibly an injector oring leaking a little and letting air into the rail very slowly over time.

duncan01

No it starts up like normal. I diddnt think about the injectors lettin air in. Im about to swap them for 24's so well see when thats done. The cars runnin awesome when it gets up to temp. If the injector was leaking air in wouldnt it push fuel out? It almost has to be injector related since every electrical part is new, everything is set where it needs to be and vacuum is where it needs to be.

2011scgt

dude what you have in mods now 19's will have no problem in handling... bump it to 12 you can go 13-14 on 89 gas... AIC? ...650 is to low 725 or so then recheck tps...does this car have k/n filter?