revs up when rolling

[crash96]

hello everyone this is my first post, so here goes. i have a 90 plymouth laser turbo. as long as i have owned the car (10 years) whenever the car moves forward or backwards in neutral or in gear with clutch in the engien revs up to about 1300 rpm. as soon as the car stops the rpms go back to normal idle. not really a huge problem but i have always wondered why this happens. its as if the iac is connected into the wheels, which as far as i know thats not so. enjoy, any help is appreciated.

 

[97 4G63]

I would try cleaning the isc that took care of my problem..

 

[My1GLaser]

I had the same car, same problem. I think it is speed sensor related to keep the rpms up for the steering pump or something, but I have no proof. I had some idle issues so I blocked off my FIAV and blocked off the coolant flow to the TB and the idle was never better and it never did it again.

 

[norrissee]

This is normal. The ecu raises the idle to compensate for powersteering, brakes, etc when the car is moving based on the speedsensor input.

I don't have a speedsensor in my car and it dies everytime I put on the brakes with the AC on

 

[crash96]

sounds good guys thanks alot