Idle Switch

[MegaSuiter]

When it is plugged in the engine hunts on idle, but when it isn't plugged in it will idle high. 1500-1700, up down occassionaly at stop lights. NEED A NEW IDLE SWITCH? i looked at the vfaq and it didn't really help me. Please chime in!

 

[turbowop]

Idle switch is either on or off. The fact that your idle changes when it is plugged in tells me that it is working fine. Your issue is elsewhere.

 

[MegaSuiter]

DAMMIT, but thank you

 

[MegaSuiter]

I unplugged my tps and nothing changed. Is this a sign of a dead tps?

 

[turbowop]

I rarely see issues with the TPS on these cars. Now that you have the idle switch plugged back in, start checking all the other usual suspects listed on the vfaq page for idle control. I would start by doing a boost leak test and then properly setting the BISS.

 

[vtecds1]

Did you test the IAC?

 

[MegaSuiter]

I honestly still don't know where the ISC is. I checked vfaq.com, looked at the diagram, and still can't seem to find it. WHERE IS IT!? Also was just driving and my hood just flew up and shattered my sunroof and cracked my windshield /ubbthreads/images/graemlins/bawling.gif

 

[turbofonz]

Usually an unplugged TPS will be an instant check engine light and almost no throttle response. It may be way out of adjustment.

 

[beaner]

The ISC is the 6 pin sensor on the bottom left.

If I were you, I would:

Make sure the throttle cable is adjusted correctly where it bolts to the intake manifold. If the cable is bolted too far to the right on the manifold, the tb has no chance to close all the way.
Connect the idle switch. Make sure it is not threaded in too far. Look at the pic above and you can see how it adjusts in and out. If it's too far in the tb has no chance to close all the way.
Turn the BISS screw in all the way, then out 2 full turns. This should get the ISC somewhere within it's range to do its thing.
Adjust the TPS correctly. Here is how. It is extremely touchy when adjusting. You have to be patient with it. Just tightening it down after clocking it will get it out of spec again. I've never seen or heard of one going bad.

If nothing changed from doing the above, I would then:

Do a vacuum/boost leak test. If there is one I would guess it's between the throttle body and head.
Test the ISC like this.
Open the ECU and visually look to see if there is anything weird going on the board. If the ISC is way out of wack for long enough, the ECU will pay the price.
Swap the coolant temp sensor.