Ok I have been reading post on here for a while now I guess it's time for me to post. K I need some help I have a 92 302 manual trans I just replaced the tps, iac, canister purge valve, pcv can't find any vacuum leaks. Here is the problem it idles fine but when I rev it up it takes a long time for the rpms to come back down to idle. It is not the throttle cable hooking up I have watched the throttle body closes right up when you let off the throttle. Problem stops when I unplug the iac but idles very low. Could a sensor be sending the iac the wrong signal making it stay open? Or could it be the tps out of adjustment? Any ideas?

 

Thy disconnecting the battery for 5 mins. to clear & rebuild the KAM.

 

Done that no fix and what is a KAM?

 

Kept adaptive memory.

 

Start by warming the engine to norm. op. temp. Then shut off the engine & disconnect the battery for 5+ minutes (not much more,you want it to pretty much remain at norm.op.temp.). Then reconnect the battery, restart and observe idle. If that didn't do it, with someone w/ their foot on the accellerator, disconnect the IAC. The idle will falter & try to stall. The person on the accelerator should catch the idle & maintain it at 675(+-)rpm. It will fight for 30-60 seconds but will settle in after that. Maintain for a minimum of 2 minutes. Then shut it off, reconnect the IAC & after 1 minute, restart. You should be looking at 675 rpm. If you have close to 675rpm, Turn on Lights, A/C, whatever you have that creates an engine load, and let idle for 2 minutes, then shut off for 1 minute. Re-rangeing the IAC is many times required after base timing is advances more than 2 degrees at a time. This assumes no Vac system leaks, a solid ignition system & no active error codes. 20 or 30 seconds at norm. op. temp, for the Idle to settle is nornal. It take at least that long to get it's sh*t together, figure out it's operating temp is & also figure out what your up to! Then adjust for all that. I don't think I already mentioned lubing the throttle cable at both ends & checking for binds. When cold starting, the idle will be higher than 675 rpm till the temp increases or you tap the accelerator. Even then it'll be a bit higher till op. temp. is reached.