randyvitaha

I have an '86 944 n/a and when I am driving down the road and go to shift....my rpm's wont drop. It is like my throttle is sticking. I rev it up a little bit and it will eventually fall.....Does anyone know what the problem is?

Luis de Prat

Let me guess... Throttle Position Switch?

I'm having some issues in my S2 purportedly caused by the same part.

Zero10

I'd check the throttle return spring, and see if the throttle wheel is gummed up.
If the throttle wheel is moving correctly, then perhaps the TPS.
What RPM's is it staying at? Is it staying up at 4000RPM, or does it drop to around 2000?

I know a bad TPS can cause it to idle around 2000RPM.

Chris_924s

Or the plug has popped off the TPS- (mine does- spring clip broke) That'll do a 2000RPM stable idle as well.

tomc_85.5_944

TPS in mine did the same thing. Fixed some bad vacuum lines I saw when I had the Throttle body off, and now I think my ISV is bad, as I get the hunting idle till the car is warm....

If you change out the TPS, remember that you might have to adjust your throttle cable afterwards....Don't ask me how I know, as I said many bad words when the rev's stayed the same after the replacement.

Maciek

I have the same problem on my 951 right now. I had the same problem with my old 87 944S. Often the TPS just needs to be adjusted rather then replaced. You can check manually to ensure your TPS is correctly adjusted by popping the hood with the engine off and playing with the throttle, when the throttle completely closes (at idle) you should hear an audible click. This means that the TPS is reading the throttle as closed and the revs should drop propery. If they don't it could mean a bad TPS. Good luck!

Tomc, what do you mean by adjusting your throttle cable? Are you talking about the minute adjustment that you can make where the throttle cable bracket bolts to the intake? If not I do not know what you're talking about and would like to know if you can further adjust it.

A tip I use to drop my revs is to lift the gas pedal with my toes and this drops the revs (just a temporary fix before I adjust my TPS, just too busy with school at the moment.)

Headhunter

Eventually the bearings in the throttle body go which causes it to stick (in my case at WOT). If it is, in fact, your TPS, I have a working spare (free) if you pay shipping. headhunter76@gmail.com

tomc_85.5_944

No, you can also adjust the throttle cable at the firewall. I mistakenly set the butterfly in the throttle fully closed (supposed to be a slight gap, comparing to others) and when I did that, and installed everything back on the car, the cable was too short, not allowing the throttle to close all the way, and keeping me from hearing the 'click'. The black tube that the cable is in can be carefully pulled out of the firewall, and adjustments can be made at the back of the tube. Had to do this to get it to work when I had the butterfly completely closed. Which made my idle strange, which is why I went back to the slight gap with the butterfly. I need to replace the ISV now, as it acts strange. Might try the fully closed butterfly with a different ISV, but for right now I'm good once I warm up....

Serge944

I feel like such a noob...i cant think of what this cable is called.

Anyways, mine had a crease in it and this would cause the throttle to stick. Would take forever for it to return to idle.

Mighty Shilling

that's cruise control dude...

Dilberto

Also, be sure the guage needle is oriented towards its stop mark on the dial.

Serge944

Yeah, thanks. I hope you're not discrediting my diagnosis though