Could somebody please help me diagnose my rough idle problem? When I come to a stoplight my rpm's will be around 650 or so and then after being stopped for about 10 seconds my idle will all the sudden drop to around 500 and then begin to get rough and you can actually see the tach moving up and down a bit! I cleaned the throttle body already, replaced plug wires. Could be some kind of sensor or something? This is a Automatic by the way.

Thanks.....in advance

 

I was having the same problem, only sometimes it would rev upo to 2000 RPM sometimes, or other times it would idle at 500 rpm. Check your intake tract for a vacuume leak.

 

I would recommend getting some Injector cleaner and Also pull your IAC vavle (Idle Air Control valve) located under the left "passenger" side of your Throttle body. Pull out that valve and clean it with some carb cleaner and put it back in. I think that will solve your problem. You will have to remove the throttle body to get to the IAC vavle.


Hope that helps,

 

Thanks for the quick reply 95 silver TA and convertz so you saying I just need to remove all the duct work and attachments from my throttle body and then remove the TB and it will be on the left side in plain view? Or what? Thank once again for the replys!!

 

<<I just need to remove all the duct work and attachments from my throttle body and then remove the TB and it will be on the left side in plain view>>

Thats exactly what I am saying. There is going to be another sensor/connector right 'above' it, that sensor is the TPS sensor 'Throttle Position sensor' ...That is not the sensor you need, you need the one right below it, the IAC sensor. When you unscrew the screws that hold this IAC sensor/vavle in place and you pull that sensor out, you will notice it has a valve like plunger in it. You just need to clean the inside of the Throttle body real good with some Carb cleaner and also clean that plunger part of the IAC sensor too. Be Aware that the Plunger part of the IAC vavle will not move freely (its not broken) that is the way it is ment to work. It take a lot of force to move it and it only moves like 1/16 of an inch at a time.

The only reason I am telling you all of this is cuz when I first cleaned my sensor I thought it was broken cuz it would not move when I tried to push and pull on it. I later found out that it was Not supposed to move easily.

Hope that helps,

 

I don't know if someone said this, but try the PCV valve....it helped out with my rough idle...........

 

Okay, So the plunger part of the IAC is what pulls out of the TB and that is the part that is going to be hard to pull out? Does this part break easily or is it a soild piece, dont want to be yanking on it to hard and break it! And also does you have to pull the whole TB off the intake?

Sorry for all the questions, but I really need to get this fixed!

 

The plunger part is the part that comes out after you unbolt the screws....You will see what I am talking about when you have the throttle body in hand. It will not be hard to take out at all nor will it take that much force to take it out....I was just saying that once you take it out and you are cleaning it, you will noticed that the plunger does not really move (if you play with it). I was just saying if you notice that, then dont be alarm... its normal.

Its kinda hard to explain with out a picture but once you take out the Throttle Body and have the IAC out, you will see exactly what I am talking about.

Dont worry about asking too many question...I was in the same spot as you before

 

I second cleaning the IAC.

 

yes, check the iac. you will need to remove the throttle body. you don't have to remove the throttle cables and all though. i think shoebox has a picture of the iac and where it is located. do a search for shoebox and on his tech page i believe he has what you need to see.