[hail2theTheif]

So I have the most random issue going on with my motor. It's a ej20g top end with an 04/05 STi shortblock, 550cc inj, and power fc.


The car is stalling after driving around a bit after warm up. So starts up great and idles great. Drive around but during that first 10 min when I go into neutral coming up to a stop light the car will just die when I take it out of gear. Only happens during first 10-15 min of driving. Smells like lots of fuel after starting right back up.

Car pulls amazing and drives totally normal after first 10-15 min and doesn't do the stalling if I were to go park somewhere run errands and then start it back up. Basically only in the morning or after not driving for a long time. Could it just be my ecu map?

I have noticed that totally randomly sometimes the idle sitting will hunt from normal (850) down to around 3-400 up and down, up and down and eventually go back to sitting at 850.

Any ideas would be great. Sorry for the long post.

Thanks!

 

[maxiav]

Will the car turn off if you just start it and let it idle for 10-15 mins?

 

[hail2theTheif]

It won't just turn off if I let it idle for 10-15. But if I let it idle 10-15 min before driving it, it will still stall once warmed up when i drive it for the first few times when I put it in neutral.

 

[Broken Motorsports]

check the parameters of the cold start. That might be where your issue is.

 

[boxcar]

Did you reset your ECU lately?

Mine always does that for awile after resetting the ECU, or switching maps, but then it goes away.

 

[hail2theTheif]

yeah i've re-initialized the ecu a few times. doesn't solve the problem.

i'm don't really know anything about cold start parameters and what they should be set at or even whats a normal setting. my buddy did the tune for his car before it went i transferred the engine and everything into my car.

any advice on what i should be looking for in the parameters?

 

[99 rs]

My car was doing the above before. It was the MAF sensor.

 

[hail2theTheif]

99rs - yeah almost exact same problem just doesn't happen all the time. plus the stall at the beginning of driving around. hmm.....

i have an extra MAF. i'll throw it in today see if it helps or changes anything.

 

[deadchip]

IAC sticking????

 

[hail2theTheif]

swapped MAFs out and the car runs a lil better. doesn't do the hunting idle anymore. only driven it a few times so can't totally confirm thats gone yet.

still stalls though on warm up ect... also noticed a nice stutter when tapping on the throttle....hmmmm

i'm wondering if it is just how the car is tuned for that area.....can do some logs but i wouldn't really know what to look for