Quote Originally Posted by Steelpanther View Post
Ive confirmed the ect sensor is reading correctly. The only thing ive noticed that soon as it fires it runs good for about 10-15 seconds after that is goes off chart lean & surges like mad and sometimes dies.
My sons 87 CSX has been doing exactly this. Car will fire up, fast idle and when it comes down do the mad surging idle and or stalling till warmed up. With the old TB we adjusted the base idle up quite a bit, made little difference.

I have not picked at it as he is suppose to be a mechanic in training and just graduated tech school and it is his car. I can tell you we checked the fuel pressure (fine) swapped out the TB for a stocker with sealed base idle screw (no difference) swapped out a MAP sensor (no difference)

I did suggest unplugging the AIS connector, effectively locking the AIS in one spot for testing. It still surged about but not as much. Clearly something is causing the idle to surge and the computer is driving the AIS in and out trying to compensate making the situation worse. Since it is still surging, I'd extrapolate that the AIS and related wiring and circuitry is not the problem at least in his case.

Gary Donovan