My car is a completely stock 91 RS, 305 tbi, 185,000 miles. And i'm having a weird problem, with no trouble codes to help.

When the engine is cold, it will only start by spraying ether in the throttle body, and it will stall immediately. However, if I start the car and manually keep the rpm's above 1000, it will stay running. If i let the rev's fall bellow 1000, it stalls.

If i keep the rpm's above 1000, until the engine comes up to temp, everything is fine and dandy. It will idle smoothly, and start everytime. Runs and drives fine.

It seems as if the injectors quit spraying at idle when the engine is cold. I have tried resetting the ecm but didn't help, and i tried unhooking the vacuum line to the egr and plugging it, which also had no effect.

I replaced the distributor cap, rotor, plug wires, and plugs about a year ago. And I changed the fuel filter and fuel pump(joy!) about 8 months ago.

BTW, this board rocks...I have done a lot of searches and a lot of reading lately...:hail:

 

now this is just the first thing that popped in my head. could it have something to do with the oil pressure switch, i dunno just a thought. you do know that there is a swicth above your oil filter that wont let the car run without a predettermined oil pressure being reached or maintained. im prolly way off base though. im trying to learn to buddy.

 

nick harmon: could you elaborate on this oil pressure switch...where it's located, how to check it, etc..

i have been reading that the ecm ignores sensor inputs when it's in open loop, which is when my car won't idle. i also read that in open loop the computer uses pre-programmed values for mixture settings. when it is in open loop mode, it backfires when i rev it. but once it gets to closed loop, everything runs perfect, no backfire, idles great, runs great.