I have been having a high idle when the car is warm and cold. The engine wouldn't idle down unless I tapped the throttle.

My vehicle is an 85 camaro sport coupe with the 2.8 mpfi v6

So I fixed that problem by removing, cleaning and reinstalling these parts:

• Maf sensor:

-Located between the air filters and the throttle body.
-Removed by unhooking wiring connector then loosening the gear clamps and sliding it out.
-Cleaned by spraying "Mass Airflow Sensor Cleaner" all over the internals of the maf sensor.
-Let it dry completely then reinstall in reverse order of removal.

*Don't touch the internals of the Maf or it will likely break.
*Don't try to clean it with carb cleaner.

• Throttle Body:

-Located downstream of the maf, on the front of the engine, has a cable attached to it.
-I didn't remove mine (I didn't feel it was needed)
-Cleaned by spraying throttle body cleaner on everything inside and using a brush to get in deep. (be sure to get in the small passages)
-Dry with a cloth and put back on if you removed it.

• IAC valve

-Located on the throttle body, top left (looking from the front of the car for 2.8L engine not sure about others)
-Remove by unhooking wiring connector then unscrewing the IAC from the throttle body
-Cleaned by holding the IAC by the base with pintle (dirty internal part) pointing downward then spraying throttle body cleaner on the pintle, spring and shaft
-Wait for it to completely dry then reinstall in reverse order of uninstall

** You need to hold the IAC with pintle pointing down because if the cleaner gets into the base of IAC it will damage it
** Carb cleaner can also be used if there is no throttle body cleaner

• TPS

-Located on throttle body below IAC (2.8L)
-I didn't remove it since its already exposed (2.8L)
-Cleaned by spraying some maf cleaner then a little wd40 on a q tip to the moving part
-Let it dry

• EGR valve

*You will need a new gasket to put the EGR back on. Its a $3.00 peice
-Located on the passenger exhaust manifold near the coil. It looks like a UFO (2.8L)
-Removed by unhooking vacuum hose off the top and removing the two bolts holding it on. I had to use penetrating old and heat to get my bolts out.
-Cleaned by scraping off the old gasket then spraying carb or throttle body cleaner all over everything with gunk on it. Reach under and push the plate up and down while spraying in the holes on the bottom.
-Let it completely dry out then reinstall by putting on new gasket and bolting it back down then reconnecting the vacuum hose.


Now your done!

At this point you can start er up or test these components to see if they are operating correctly. Most of these parts can be tested with only a multimeter, your finger and some jumper cables.

Do a search on how to test these parts. I'm not sure if I'm allowed to put a link to them so I wont risk it.


Doing these steps fixed my high idle and it also partially stopped my car from stumbling, throwing a code 45, then revving back up at idle.

Always more work to do.

I hope this is helpful to someone.
-Marek

 

Love this but really need pictures need to do this before put car on rode i have to deal with the high idleing then when put it in drive dealing with it jumping in that gear then dropping down.

 

I will add pictures when I get the car out of the garage for the winter.

To add on to my conclusion. The high idle is back. It seems to have gotten worse since it got colder out. Now it wont even go down by tapping the throttle.. Just up and up then eventually it will come down.

I'm going to reclean the throttle body and check the throttle cable in the spring.

 

Your throttle shaft bores are probably worn.

 

How would I check that?

 

When it's idling high, see if the throttle is hanging open slightly. Usually it will happen only when the engine is running, not when it's stopped.

 

started my car now in the cold did throttle body cleaner? and it idles in the cold at 1500 not 2000 now is this better. Cleaned of the gold ring. Is there anyway i can get rid of that and run a smaller air fliter because im running big 14" inch one?

 

I'm sure you can get a smaller air filter. I have a fuel injected engine so I haven't looked at any air filters for a carb engine.

 

So your saying if i get smaller air filter and also take that ring off what else what it do i know not much but would suck in air better and keep less dirt and odds and ends.

 

I couldn't tell you if it would be better or worse because I don't know anything about air filters

 

All i know stock restricts but keep the stock one so when you sell the car it will go with it and look completely stock. People love stock cars.