i am having a consistent idling issue with my 1999 turbo c70 coupe 2.4L. i have done plenty of research on this topic and have already replaced my old throttle body with the yellow label version and even cleaned the replacement thoroughly before installing. Upon putting everything back together and starting it up, after about 10 minutes it began to steady out. i was assuming itd be necessary to allow the car to reacclimate to a new an unfamiliar piece of machinery. i took it on a test drive and everything worked great. i thought i was good to go...

until this morning, i go to start it up and once again, back to an idling issue. While it is a similar idle issue as before, where it would spike up and down between about 500 to 1000 rpms continuously and even want to go on me at a stop light and even to the point where acceleration was being affected (and dangerous to drive).

However, with the replacement throttle body,while it has begun to spike between 500-1000 rpms again after installation, it will also rev up even higher (up to ~2500-3000rpms) as if it is trying to find a steady spot to settle out. and my acceleration is unaffected. it seems as though it might be something else now, but i am not sure.

My question is what else could it be that is causing this issue? i have read about needing to reprogram a new throttle body after replacing an old one. However, i have yet to do this since my mechanic said that if the one i bought (which was used) came off the same exact car that it may not need to be reprogrammed. While i am now beginning to question this, i also want to see if there is something else it might be?

i have read about it maybe being the TPS and also read about replacing the MAF sensor, but many times i have read people have done this and it did not work. and even read about cleaning off the engine crank sensor that might have build up gunk on it...

Regardless, i am really just looking for a more expert opinion with my problem as i am not a mechanic in any way and do not want to go replacing a bunch of parts for no reason, let alone the cost to do all of this.

My thinking is i should get a diagnosis from the dealer, but im afraid all they will tell me is that i should replace or clean the throttle body because they want my money, both of which have already been done as i explained earlier.

I greatly appreciate any help or possible solutions that could be offered to remedy this problem as i know just about every older model c70 owner has or will run into this issue eventually since volvo wants to hide behind bs extended warranties for a part they know is defective.

thank you

 

Replace WOT sensor!

 

i cannot find anything on a wot sensor, is there another name for it? or is this just the TPS?