I have an '89 crx si 5 speed, the check engine light has been on for quite some time. It is a code 8 which is tdc position sensor, the car has been running excelent with the light on until very recently. It now will rev up all on it's own. Usually at an idle at a light or stop sign it will just start to rev up, getting as high as 5k before I turn it off. It will also ocassionally do it while driving. I am looking for sugestions and wondering if anyone else has encountered this. Thanks.

 

Your throttle body has a flat tip screw on it which faces the passanger side of the car. Check this to make sure it has not loosend up and backed out a bit. If this is loose it will cause irradic idle problems.

 

I would replace the distributor to see if that solves the problem (internal sensors can't be replaced independetly). The idle adjustment screw would not make it rev as high as 5k.

 

A BIG vacuum leak would also cause this. But it would do it all the time, and by your post i couldnt tell if thats the case. Good luck

 

Thanks for the suggestions. The car does not do it all the time, very intermittant. I will check the screw. I've been hesitant to change the distributor as I hate to spend the money unless I'm confidant it's the problem. Any thoughts that it could be the computer?

 

on the back of the throttle body there is a sensor( throttle position sensor) it sounds like it has went bad. i would change it first

 

I have a 90 Hatch and I have had the same problem. It has only happened a couple of times but it is kind of weird. It just starts revving on it's own. Sometimes it goes real high but just today it would go to like 2K and then back down. Weird. It has not happened often enough to try and fix it yet though. Let me know what you find out....

 

when i first got my rex abourt 2 months ago i encoutered that problem as well.... my situation was my excelleration cable was getting pined by the hood. soo every once in a while it would get stuck and shoot sky high. i think i was at about 5000 or 6000. just check that wire and see if its all loose. if soo just tuck it away

 

In my case it was the throttle kicker valve located on the front of the throttlebody. It helps maintain idle when the engines experiences a drain from A/C or other electrical drains. I dont have A/C so i took it completly off no probs anymore.
Rick