poltergeist 02

iTrader: (65)

just wondering if anybody has run into this before? it's an ls1 with a 228/230 cam, ported stock tb,slp lid, long tubes, ory, 3600 stall. the car has been dyno tuned. this only happens on a start after the car has sat for a few hours. if i start the car it will fire up and then die. if i start the car and give it a little throttle it will rev and then idle fine. i'm at a loss here. just hoping someone can help me out with some good input. thanks guys!

Darkman

iTrader: (2)

One possibility is a leaky fuel injector. If that were the case you would probably also be experiencing some dieseling at shut down.

KevinR

My guess is that you may need to take it back to where you got it tuned and tell them to work on the cold start.

02sslayer

iTrader: (4)

my car does the same thing, but its kinda funny. if i have the heater or ac running when i start the car it will start idle a couple times then die.

poltergeist 02

iTrader: (65)

i was thinking the same thing but the car only has 25k on the clock. could a injector go bad from sitting or from age?

1Hawk

I could almost gaurantee you its the open loop tune...or cold start tune...I doubt its mechanical

DaddySS

Thre's are a few sections of the tune specifically for starting - one of them is start up friction which gives the engine a few seconds of extra idle and then decays quickly - it sounds like you need to fine tune the start up tune.

Have a look here and you can see what I mean:

https://ls1tech.com/forums/pcm-diagn...er-tuning.html

Darkman

iTrader: (2)

The normal causes for a leaky injector include wear or accumulation of contaminants that prevent the internal pintle valve from closing. Contamination can include gasoline that has aged from sitting.

poltergeist 02

iTrader: (65)

i was looking through this thread and it seems to help your idle if your idle isn't good at all. my situation is a little different. the car only won't idle on a startup after the car has sat for a while. after you let it run for 30 seconds or so you can shut it off and it will start back up just fine.

KevinR

I very seriously doubt that it's an injector and that it's in the tune. Did it start having this problem right after you got the car tuned?

poltergeist 02

iTrader: (65)

yes, it started happening right after the cam swap/tune. if i do the tps relearn will that mess up the tune at all? does this sound like something that actualy has a chance of helping my situation?

poltergeist 02

iTrader: (65)

ok, i tried it and still the same. maybe it is in the tune.

blsnelling

iTrader: (4)

Highly unlikely it's anything but the tune.