5KsTQ Throttle Switch (Idle/WOT)

[scott.john.mockry@bangate1.tek.com]

Steve,

When I took apart the throttle switches on my 89 200TQ and on the 86 5KCST I did not find the
WOT switch bent or misaligned. The contacts were just a little dirty/corroded. Your problem does
sound intriguing to say the least. I would bet that there are many 5K's and 200's running around
with intermittant/defective throttle switches.

 If I remember correctly  the ECU uses the WOT (2/3 throttle  opening) switch signal to activate 
the  turbo boost modulation program using the internal ROM boost map and the boost control 
solenoid connected to the  waste gate. The driver may not even notice if the WOT switch is 
defective. The fault memory should indicate this sort of a problem if the vehicle is left running 
after a failure of the WOT  switch occurs. 

On a related note: if you disconnect the idle stablizer valve electrical connector while the engine
 is running the idle stablizer control relay will shut off the signal  to the valve. It will be shut 
off until the engine  is turned off and then restarted. I was looking at my new repair manual 
(on micro-fische) and it  mentions this fact along with the procedure for measuring the current 
into the idle stablizer valve and adjusting the idle speed until the current into the valve is 
430 mA + or - 10mA. This assumes the crankcase breather hose is disconnected and plugged 
going into the intake manifold and the canister purge hose cap is removed. This idle adjustment
procedure is slightly different for the late (11/88) 89 model 200 Turbo vehicles. 

P.S. Thanks for the tip on the windshield washer check  valve removal. My 89 200TQ washers
spray much better now without that damn thing. The previous drizzle effect was getting old real
quick......

Scott M.


>From: steveb@newkla.kla.com
>Date: Tue, 30 Jan 1996 08:34:39 -0800
>Subject: 5kT: Idle/full throttle switch

>I had heard people talking about failures in the switches that indicate
>idle and full throttle positions to the ECU, so I decided to test the
>one on the '885kCSTQW.  I found that the idle switch worked fine, but
>I never got a switch closure on the WOT switch.  I disassembled the 
>switch to find that the moving contact was bent in such a way as to 
>never make contact. TEXT DELETED