Hi,

I'm having this nightmare problem, my cars a 1989 rs, 305 tbi auto. When I hit a bump in the road the idle increases hell of alot, service soon light comes on and the auto box will come out of overdrive

I'm in England and the people dont seem to have a code tester either. So was wondering if anyone came across this, or have any suggestions for things to look at?

any help much appreciated,

Dane

 

Does the idle go back down afterwards?

 

Here's my guess: Broken brake booster hose flexes as engine compartment warms up and reveals crack when you drive over a bump causing a vacuum leak.

???

 

after a couple of minutes it will go back to running smooth, or turning the car off and on again

 

go out and run the car while wiggling wires and hoses in the engine compartment.
Hopefully the problem will rear it's ugly head for you....

 

I had a bad computer once. I could tap on it while the engine was running and the idle would change.

 

Start wiggling everything on the harness and spray the engine bay with ether. Ether will find any vacuum leaks. If you lose vacuum anywhere near the booster it will try to create vacuum on it's own by hiking up the RPMs.

 

Sorry, whats ether? never heard of it?