On my 90 GXL, I have 2 clutch switches- One appears to be affected when the clutch is all the way up- it's a plunger on the front of the clutch pedal shaft.
The second is on the firewall, and is affected when the clutch is depressed fully.

I have had the one on the firewall disconnected for quites some time due to my remote starter.
It just occured to me- which one does the ECU factor in when controlling decell and idle? Cause my idle is funky!
Thanks

 

The one on the firewall contreols the starter interlock **** that requires pushing of the clutch to start the car, which you have disabled. The other one is for cruise control(some cars had it that were not equipped also), so that if you push in the clutch at all it disengages cruise just like the brake pedal. In my 90 FSm teh only input to the ECU listed for clutch is the starter interlock one.

 

Im going to have to check into that, see if it is causing my 1500 rpm!!!!!!! idle on a stock port motor. I cannot get the car to go below 1500 rpm. All of the idle adjustment screws are all the way down, I plugged the small hole in the primary throttle plate, still wont go below 1500.

Let me know if you find anything else, and Ill check mine out tomorrow.

 

Take a look at the 90+ FSM on fc3s.org
It shows really great relationship/flowcharts on how the ECU determines conditions. The clutch is a factor in decell and idle, it just doesn't explain how.

 

It's the bottom one that causes the stupid idle!

It looks like it's a common problem that the plastic stopper on the clutch pedal lever disintegrates into tiny pieces!&nbsp When this happens, the clutch switch slips into the now-vacant hole; if you get a clicking noise when you get off the pedal, this is your problem.

As stupid as it seems, if this is your case, you'll end up with a higher than normal idle (over 1,000RPM)!



-Ted

 

THANK YOU!!!!!!!!

You just described my exact problem. I cannot adjust my idle down from 1500 rpm, and the clutch clicks when you let off.

Is there a way I can bypass that switch, or should I just replace it.

 

I didn't bypass it.&nbsp What my solution was...

I used to play pool/billiards a lot so I always come across all these leather tips that had flown off the cue sticks.&nbsp I used some epoxy and stuck one of those leather tips onto my clutch pedal lever.&nbsp It's still there, and it prevents the stupid switch from clicking into the hole!

You can pretty much use anything close like that (piece of rubber?) that you can glue in there...

Good luck!

Ain't these cars a bitch?


-Ted

 

My car still has a plastic stopper there. But I checked the switch out, and it was dead. So I replaced it with a good one from my parts car. But it didnt help my idle.

Heres my idle problems: its very high most of the time, fluctuating between 1300-1500 rpm. If you rev the engine and let off the gas, the rpms fall to 1K, stumble a good bit, then they begin to rise back to 1300-1500. It seems like the ECU wont let my car idle low. Sometimes the car keeps stumbling, and the engine stalls.

I have no emissions stuff on my car, no air pump, all vacuum nipples blocked off(the only one IM using is for the FPR), no a/c, no p/s. My car runs noticable rich at idle. The stumbling/stalling I believe is due to it running so rich it wont run right, but I dont know why. I have stock fuel system.

One quick queston, when the clutch switch messes up the idle, does the switch itself have continuity or not? If I was to bypass it to where it does not raise the idle, would I splice the 2 wires going into it, or just unplug it?

 

bump