High Idle
 

High cold start in 2000 rpm range ... backing up and starting from a stop is a little rough ...
It frops to 1200 ish rpms after a drive ..

Highway is smooth as can be ..

Recently changed plugs wires and spray and brushed the plenum out .. everything is back to normal except high idle

High idle
 

You either have an idle control motor stuck open or a real nasty vacuum leak. somewhere unmetered air is getting into the engine.

Hope this helps.

Thanks for your reply .. You were right about the IAC !! I toolk the air box off and stuck my finger over the hole that leads to the IAC.. started right up and idled great !!

flew up to autozone and got me a new IAC. Came back and installed it but something told me to try out my old PCM .. so I put that back on too ..

no so good of results with the old one.. I still need to give it gas to start and needs to be revved up a bit to get it going .. it runs and once accelerated it drives just like she use to ..

Im going to throw in my new PCM again and maybe even try to blow out the IAC hole better (IAC removed of course ) ..

If its not the PCM I have a feeling I fried another sensor .. maybe the map or tps .. check the voltages on those again too when i get home this afternoon



But all in all THANKS AGAIN !!

well I ended up changing out the map with one from the junk yard and seemed to put and end to high idle momentarily .. engine light went off (i reset and drove a few times)..

then going to Burger King I get in a high Idle .. DAM IT !! So i popped the hood and tried wiggling the two sensors left that havent been changed. The TPS and EGR ..

upon wiggling the TPS i found maybe the plug has lose terminal or that when wiggling the TPS is not properly tightened down with an ever so slight movement. When I wiggle the wires it revs up and will stay .. wiggle them again and hit the right spot and it will go back down ... I will change plug tomorrow.

Should I go ahead and grab another sensor ? I tested with volt meter and tested out fine .. something tells me though that since i ruined the other two sensors I prob did the same spraying the TB out ..

Any other suggestions for testing ? or checking ?

slight engine shake at stop signs else a smooth ride.. or when in park idling it revs slightly .. backing up you get kind of a shake from engine but no erratic rpm's or stalling ..

Sometimes just unplugging and plug back in a few times will fix most problems. the iac is controlled by many things. here is whare a good scan tool comes into play. you need to check the engine coolant in the morning BEFORE starting. here is the reason. if the ect engine coolant temperature sensor tells the pcm it's -40 then the pcm will keep the iac open to keep the engine running longer.it is lying to the pcm and if it says it's 245 then it will stall when cold because the pcm thinks the engine is warm and keep it closed. if you have any doubt there is a ohm reading for both hot and cold you need to look it up if you don't have access to a scanner. if it stays in the cold run mode like an open thermostat it will dump fuel to keep the engine running and eventually destroy the catalytic converter. this is why you need a good thermostat summer and winter also. I had a pickup come in with a stalling problem when it's cold. checked the coolant temp says 235 when it was 28 out side. new ect corrected the problem.

Hope this sheds some light on your problem.

One more thing. if you are going to change plugs on any sensor make sure you use heat shrink tube and solder connections. moisture is an enemy.