91gs starts and shuts right down

[jo_91gs]

ok, so i get home from a long trip in the -91 2.0 nt 5 spd-, next morning start it and it wont stay on. ive had this problem before and, with Old Mitsu Tech's advice, found out it was my ecu. i replaced it, and the car has been running great until now. opened up the rebuilt ecu and no signs of damage, but since still on warranty replace it anyways but no difference. the problem i -sometimes- had on the road though was that while running with the ac, my idle tends to fall and car turns off as soon as i push the clutch (drop in into nuetral). oh let me just add that i only use my ac on long trips because of this so yeah ive had this problem for quite a while. anyways while making a few stops on the road i realize it starts doing the same thing (the idle falling) without the ac turned on. but at the time it would turn back on and work, but only for a few moments. so again id appreciate any advice from anyone who has had this problem or has any ideas on why this is happening. i hope this little info helps...

 

[Bruno96]

try replacing the iac

 

[jdhutchin]

I'd check the BISS setting and make sure it's set right, then maybe check the ISC.

 

[jo_91gs]

after doing alot of research, and after almost about 6 months of these idle related problems and finding out other things related to the isc, im more than sure it is my isc, but one more thing. if you isc completely goes out, will your car not want to stay on after starting it?

 

[jdhutchin]

It depends where the ISC got stuck at. If it's stuck all the way closed, it's possible that not enough air can get through for the car to idle. If it gets stuck somewhere in the middle, you'll get an idle surge.

Try backing the BISS out- you might be able to get your car to idle then and at least run some until you get the new ISC in.

 

[jo_91gs]

Ecu rebuild solved the problem.