Hello all, let me first start by thanking everyone here for your help in the past. this is my first post and maybe you can help.
when i first start my car it will idle up to about 1500rpm for about 45 seconds befor it drops down to about between 900 and 750 where it bounce around in a surging type manor. now i have cleaned the iac sensor and adjusted the tps, checked the plugs, wires and dis cap. and this is all on my 86 iroc 305. is there somthing im missing or should i replace these sensors.

 

maybe the coil?

 

did you check for vacuum leaks? especially on the intake duct for a tpi motor,

 

check your coolant temperature sensor and oxygen sensor

 

replaced the o2 sensor already, i had to when i first bought the car because the previous owner broke it. i'll be checking the exhuast this weekend because i've heard that a restriction can cause the same symptons.

 

Someone has the "wright" idea. Eliminate all potential vacuum leaks. That includes the EGR, PCV, brake booster, hoses, gaskets, etcetera.

Make sure the fuel pressure is steady.

Make sure the FPR is not leaking through. You can remove the vacuum line from the FPR to check for leakage.

The higher RPM at startup is normal for stock programming, even when the engine is warm. The idle RPM can wander a bit, so long as it is steady when idling in DRIVE. And you need to make sure you are using a separate tachometer to read the RPM and adjust the minimum air position instead of relying on the in-dash "tachometer".

 

i found it, vacuum leak on a couple of hoses. ( damn hoe's lol ). the little red roc is feeling pretty good, thanks everyone!