I've got an 83 Z/28 with crossfire inj. I've been trying to fix two problems with little luck...

I have an intermittant surging idle (@500 to 1700 rpm), occasional stalling at traffic lights (the cowl induction starts flipping open and closed just before it stalls), and it sometimes stalls after shifting from Park to any gear (auto trans) all after it is warmed up (closed loop). It acts to me like is not getting enough air for the engine to keep running.

The second problem is that if this were a carburated car I would swear the accelerator pump was bad, it kind of caves in when accelerating from idle under normal driving. If you get into it hard, after it caves in, it (almost always) catches up with itself and really scoots. Anytime other than idle related, the thing runs great.

I've checked the voltage at the TPS and it seems within specs and increases smoothly, I've fixed all the vacuum leaks, replaced the MAP sensor, O2 sensor and Temp Cont. Sensor, and a fresh tune up. Before I go and replace the IAC sensors and Computer, can anyone give me any suggestions.

I'm not getting any repeat codes that help diagnosing it either.

The car is in great shape otherwise, I can't, in good conscience, even sell it in this condition. Help!!!!

Thanks

 

IF!! the tps voltage is correct, there are NO vaccum leaks (check the intake itself!) and the map, and temp are working properly, Id go ahead and check the IAC motors. and if there good get a reman ECM and try it. (if it dosent fix the problem you can always return it.)

 

Don't know much, but try checking the timing.

 

DOH! ^^^^^^^^^^ what he said.

and be shure the ESC is pluged in.

 

check your fuel pressure? my TBI did the SAME thing exactly and i fought it an fought it didnt know what it was till the fuel pump finally went out...was the fuel pump the whole time...30$ part and a major pain in the *** later and it ran perfect....check that before you go selling it.