well i have a 91 std i bought it 3 months ago. well when the car is cold the car drives really good but when it gets warmed up it starts idleing nonstop and revs by its self. i already cleaned the iacv with carb cleaner, and it still does the same thing. can anyone help me because im soo frustrated with it i stopped driving it . and said to myself im not going to drive it till i fix it. one of my dads "friendly machanics" said it has to do something with the pistons or something. to be honest i dont belive him. but i will trust you guys because all yall helped me b4 and you know who yall are. well please help me. ill appreciate it. thanks for taking your time and reading this.

 

what do you mean starts idleing nonstop? it idles too high or too low? and when you say revs by itself does it keep going up and down by it self?

 

when its all warmed up it idles and it wont stop until i turned it off. it idles low. and about the reving when im driving and come to a stop and have no gears it it keeps acceletaring only alittle y its self.

 

any vacuum leaks crackes manifold etc

 

sounds possilby like a vacuum leak or a problem with the IAC. try changing the iac with a used one if you can. one that you know the engine was running good with it, aybe a buddies. and if not, try spraying brake cleens around the engine bay, on all the vacuum lines to see if you've got a vacuum leak. if you dont know, the engine will rev higher if it has a vacuum leak and brake cleens gets into it.
im interested to know what the outcome is. Lemme know