2 pin idle switch (JT 4kq - Starting Issues Solved)

[Johnny B]

I have verified the idle switch has failed in the open position so the car never believes its at idle (checked with a voltmeter, and finally left it unplugged and drove around, no change). I'm certain because of this on initial start up the car is throwing itself in to closed loop mode (lean & efficient mode) and ignoring the coolant temperature sensor telling it to go full rich until that first minute or so while the o2 warms up to start telling the ECU how much fuel to deliver. Once the o2 comes up to temp all the issues go away as the ECU can now regulate proper fuel delivery to mask the idle switch failure. 

When I had first checked the switch I only looked to see if it was open with the throttle open on the voltmeter, but must have been moving too quickly and never checked the closed position. Luckily while sprucing up under the hood I realized I didnt hear the audible *click* when the throttle is opened a tad.. this lead me down to retesting the switch and ultimately finding it has failed. I have lucked out and have several switches now I can install, only problem is a rounded out throttle body bolt for me to take care of this weekend (going to have to drill or chisel the head off or something, looks mighty FUBAR'd). 

As for physical damage, I was able to get a good look at the switch and it seems the arm for the trigger is completely gone. My plan is to retain the switch body and build a new arm for it just to have something on the shelf for the future. 

Johnny

> Date: Thu, 26 Aug 2010 08:51:47 -0700
> From: msvphoto at pacbell.net
> Subject: Re: 2 pin idle switch (JT 4kq)
> To: quattro at audifans.com; pre95 at live.com
> 
> Have you verified the switch is bad and part of the cause of your poor start 
> issues? 
> 
> If it is not physically damaged you might be able to repair it with a relay 
> contact burnishing tool and some high end contact cleaner such as Caig or 
> Stabilant.
> 
> Good luck and let us know what finally fixes your 4kq start issues.
> 
> Mike Veglia
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