My car is a project car. 1986 tpi 5.0 v8 automatic trans am.i'm tearing my hair out over this and now i think i'm on the right track.my car almost never stays running after i first start it in teh morning cold.takes 3-4 tries now for it to stay running and it searches for idle.then warms up and is fine. idles consistanly around 800-900. a little high but sounds healthy.but i want it to start and run good right from the start. after thinking about fuel pressure, fuel pump, 02 sensor, fuel injectors, maf, maf relays, air filter, IAC, TPS, vacuum leaks, oil,etc... most of these can be checked off the list of possibiliies because car runs fine once warmed up.now after learning about air divert valves and air pumps etc....could this be more likely what my problem is? and where do i begin to start testing?

 

Done a tune up?
Sparkplugs with correct gap first, then rotor, cap, and wires.

 

sry forgot to mention been there done that new cap new plugs with correct gap, new rotor and even new ignition module
----------
car runs and drives fine once at operating temperature. not as much power as i would expect from a v8 tpi but i'm still tweaking. fuel inejctors and adjustable fuel pressure regulator might be in the near future.

but just trying to keep it running at first cold is my problem and it has rough searching idle gassping for something and dies unless i tap teh gas pedal.

eventually it will sustane it self on 3rd-4th try and warm up and be fine

so ive done reading up on air divert valve that controls air into the system until the ecm takes complete control. or something along those lines


anyone with knowledge of teh air divert valve system think a solenoid or leak may be my problem?

 

The injected air is only pumped to the exhaust manifolds, to the converter, or dumped to atmosphere. Even if all the valves were stuck or have failed, it shouldn't affect cold startup operation. If the port valve sticks open, the extra air can be a problem once the engine is warmed and in closed loop, since the extra air can "fool" the oxygen sensor into reading an artificially lean mixture.

 

ok well the car passed emmisons beautifully a few months ago. new o2 sensor(BOSCH brand) but now im getting a code 44 lean o2 code.

still gotta check a few things and i just added air divert valve to my possible suspect list.

cold start problem can be so many things its sickening.


just wondering what i should concentrate my attention the most when car idles better and runs better at operating temp. to solve my cold start problem. cuz some things liek a vacuum leak would make my car run like crap all the time i would think.

i guess ineed to rule out a few more things before anyone can help me