i just dropped my my motor in..its a gsr 12.1:1 engine. stock injectors and stock ecu(ob2). if i go to start the car while its cold itll idle fine.but after a while itll just die. why wont it stay on?

 

Check fuel pressure. If it dies after the engine gets to a certain temp it could be your vapor locking your fuel delivery system. Also how hot dose the engine temp get. Could be you are over heating and your cooling system is performaning as it should.


Shove a fan infront of your car and put that bitch on high. Start the car and see if it dies or not.

 

no itll only idle for about a min b4 it shuts off..its definitly not that its overheating. for ex. i can start the car cold as soon as i try driving it it will shut off even if cold..

 

Maybe an iac issue? How are you monitoring a/f ratio?

 

to be honest im not monitering it..but shouldnt it be fine if its running stock ecu stock injectors and stock fuel pressure regulator

 

A 12:1 compression motor requires more fuel. The ecu will make some adjustment, but I dont think stock injectors with stock fuel pressure is enough. You may be able to get it to run but I wouldnt run it hard like that.

 

ya, i was thinking something like that. thats why i mentioned that it was at 12.1:1 to see if that mattered. i was planning on throwing 440 cc injectors in it along with an aem fuel pressure regulator. with the tune should this problem be reseolved?

 

It's starving for fuel. I bet it's pinging like crazy underload as well.

 

i dont feel that its pinging but should the tune resolve this issue?

 

tune the sucker...your killing your motor slowly by not feeding it enough fuel...gsr ecu's are only good for stock gsr motors...especially obd2

 

thx..thats what i was thinking..

 

having the same exact problem with turbo non vtec setup fully rebuilt. running aem fpr still having a prob. going to put in a different iacv in a little and see. if that doesnt do it i have been reading ignition timing might be it and going to adjust it. let me know if u figure it out on your end.