Once in awhile when I put my car in park or into neutral the idle goes up to around 1300-1500 rpms and stays there for 15 or 20 seconds then it will idle back down to between 700-900 rpms. It seems to be fine when it is in gear.

Could this be my tps? It doesn't do it all the time so I'm kinda stumped.

It's a 86 305 TPI motor. Thanks

 

Had a similar problem with my 89 Formula. All i did was adjust the throttle position sensor and it helped immensely. Probably a temporary fix but it saved me $30 for now. Steve

 

did you do anything to the motor??

Its normal for the cars, on start up, and when put in park to revv up a bit. Thats the IAC working (I believe). However if you are in 1500RPM range for more than couple of seconds than something is either stuck or open.

I would look at cleaning the IAC. Just take it out and spray it with some sensor safe cleaner. It should clean the gunk off and allow full motion for the IAC. Also, as stated before, check to voltage on your TPS (throttle position sensor). Sometimes it gets out of whack and it might have a flat spot (so to speak) where the voltage is the same even though the throttle is varying.

Replacing these things every couple of years is something that would save you many headaches down the road.

Let us know how it goes.

P.S. If you don't know how to do the previously described things just go to thirdgen.org and on the main page look for Tech Articles. It will describe the procedures to ya. Pretty easy stuff.

 

Other than a homemade CAI and chip the car is all stock.

I've owned the car since new and it never did it to this extent before just lately it started idling higher. It always did shoot up just for a second when you put it in park but it seems to be holding on to that higher rpm longer now.

Thanks for the input.