What did I do wrong?
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Joined: May 2000
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What did I do wrong?
Yesterday I replaced my thermostat and it solved my overheating problem. I also took off the intercooler hose to check for cracks and took off the multi-function temperature sensor to check for bad connections. The IC hose was fine and I sprayed the MFTS with contact spray.
When I took the 865KQ for a test drive, it was suddenly idling at almost 3000 rpm. At one point I let off the gas and the car was not decelerating. It continued at the same speed and would only slow down if I applied the brake.
I turned the idle screw all the way down, cleaned out the ISV, and re-soldered the connections inside the Throttle Switch. Nothing helped. The throttle cable appears fine.
Is there anything else I should check before bringing it to a garage?
When I took the 865KQ for a test drive, it was suddenly idling at almost 3000 rpm. At one point I let off the gas and the car was not decelerating. It continued at the same speed and would only slow down if I applied the brake.
I turned the idle screw all the way down, cleaned out the ISV, and re-soldered the connections inside the Throttle Switch. Nothing helped. The throttle cable appears fine.
Is there anything else I should check before bringing it to a garage?
AudiWorld Senior Member
Joined: Mar 2000
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Re: What did I do wrong?
I had the same problem with my 89 200q, had to buy new ISV. What a nice surprise to come off throttle and accelerate into stopped traffic.....
aaahhhh....
You should also check all of your crankcase breather hoses condition and clean them if necessary...
And yes you have to send your ECU out to be modified.
aaahhhh....
You should also check all of your crankcase breather hoses condition and clean them if necessary...
And yes you have to send your ECU out to be modified.
Thread Starter
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Joined: May 2000
Posts: 34
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Re: Also check the idle switch and the decel valve
Took off ISV again and sprayed it again. Also rapped it a few times against my hard head. Waiting for it to dry out.
Something that might give a clue to what the problem is:
1) I unplugged the ISV while it was running and it made absolutely no difference. Idle stayed high.
2) Disconnected the throttle switch. Again everything stayed the same.
When I took off the intercooler boot, could this have affected the throttle in some way? Just reaching now.
Would a bad ISV cause the car to not decelerate when driving?
Something that might give a clue to what the problem is:
1) I unplugged the ISV while it was running and it made absolutely no difference. Idle stayed high.
2) Disconnected the throttle switch. Again everything stayed the same.
When I took off the intercooler boot, could this have affected the throttle in some way? Just reaching now.
Would a bad ISV cause the car to not decelerate when driving?
Junior Member
Joined: Mar 2000
Posts: 1,800
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A stuck ISV should make the revs jump harshly from 1200-1800 when at idle.
As the decel valve kicks in and out. The decel valve runs off of the idle switch. Take the ISV out, cove one end with thick sheet plastic, and put it back in. This heavy garbage bag or whatever you find will block the flow through the ISV. Adjust your idle screw and off you go!<p>Todd W
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