okay. so.

wtf is that other clutch switch on the pedal for?



when the clutch is pressed in enough to trip the switch, the cars idle bounces around 1500.



when the clutch is out and the switch isnt tripped, the engine shakes and the idle slowly drops to around 1000.



and this doesnt make any sense to me. any one have any ideas?



the tps is adjusted perfect. The idle a/f screw does nothing. The idle screw is tightened all the way down, and unscrewing it any doesnt really do anything.

i'm assuming its a vacuum leak making it bounce but i cant find it. besides that the clutch switch thing changing the idle is completely confusing me.

one is for the neutral safey switch and the other one not so sure,,,,,,,,, the switch wich gets tripped when the pedal is all the way to the floor is the neutral switch. and why it has any affect on your idle could be a ground fault or that much of a serious air leak. do the good ol times trick of brake cleaner and spray the intake down and see if you can find the leak. also make sure your maf is not stuck open



randy

its not the neutral switch, its the other one. and its the switch causing the idle change because when i crawl under there and push it in myself it changes. and when its unlugged it idles all shakey like it would without me touching the clutch.



i tried moving the afm around to make sure it just wasnt at the wrong angle, no luck.

i'll try brake cleaner tomorrow. i've tried starting spray but can never find one that actually works right.

one is the starter interlock switch, lets the car crank or not, obviously.



other is the clutch switch. Goes to terminal 1Q on the ECU. Page Z-32 and Z-34 in the wiring schematic book. Page F2-84 in the FSM, also F2-77 (unless it's n/a, then it should be F1-84 and F1-77).



With clutch released, KOEO, should see 12v at pin 1Q.

Clutch depressed, KOEO, should see below 2v at 1Q.



It's simply a wire from the PCM (1Q), to the switch, then from the switch to ground. the wire from the PCM is shared with part of the cruise control wiring.



Other then that i really dont think the switch does anything, just lets the car know when the clutch is pushed in and out.



do you still have a BAC? what exact idle controls do you have left? this is why i strip all my 7's down to only 2 adjusters (well three if you count the throttle cable).



the "neutral switch" is on the trans. damn lee if you just lived close to me id have your car running smoothly, idle is my specialty lol, i had a blown motor idling nicely lol.



kevin.

yeah im back to NA. although the car never idled right when it was turbo either.



ive had three 88 fc's and two different motors in this particular one. i have never been able to get one to idle normal. its so frustrating.



i still have a bac and all emissions. trying to get some money scraped up for a header then do complete emissions removal. stupid one piece exhaust with a cat.



i wanna to a megasquirt and tii intake manifolds on NA, but im broker then broke.



so the switch doesnt really do anything important, but its affecting the idle which is confusing as ****.

You shouldnt be idling around 1500 anyway.

Bring the engine to a steady 750ish, and get your idle controls right or remove them. Then you can retune or replace that tps.

yes i figure theres a vacuum leak causing the high idle. but the switch thing is completely throwing me off.

i emptied a can of flammible brake cleaner into the engine bay.



didnt find oooone leak.



if i pulled a vac line off and spray the cleaner into it the idle jumped up like it should.



but even resorting to completely spray bombing every bit of vacuum line and flange on the engine in mass amounts didnt cause one jump in idle.



could the bac coolant lines being kinda shitty make it jump?



im out of ideas here.

For the longest time with my fc, i couldnt get it to idle down below 1100 rpm, no matter what i did with the TB. Even without the BAC or any of the emissions stuff, it was the same deal. But it was prone to stalling if you abruptly let off the gas. But after bypassing that switch(which was bad upon inspection), I had to raise my base idle to get it to the 750-800 rpm it should be at. And my stalling issue went away completely. I believe that switch triggers a change in the ignition timing and/or fuel at idle. But for what purpose, I dont really know. I snipped the wires before the plug, and soldered them together, and forgot about it.

mines being the opposite though.



if i wired the switch up like you did, it would idle bouncing around 1500.



if i unplugged it and didnt wire it up, it would be at 1000ish motor shakin town.