Hello all. I've just checked my tps with a multimeter as I've been having a rough idle when the engine is cold and an idle of upto a 1000 once warm. It didn't go short circuit on pins 1 and 3 when the throttle was fully opened. What does this mean for driving the car?
I'm going to get all the gaskets etc then drill a hole in the tps and spray carb cleaner. Is this likely to fix it or will the tps need to be removed and cleaned properly? Many thanks
TPS test result
Moderator: martauto
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pianist
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Is it m20 you on about? Because if it is TPS is not potentiometer type but micro switch, it has 3 pin connector and I don't remember what pin numbers are but the pin in the middle makes contact with left and right pins one at a time on throttle closed and then wide open so spraying it will deffo make it worse.
Ps. You need to do continuity test when checking them pins
Ps. You need to do continuity test when checking them pins
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tha881
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Thanks its a 325i. I did the test as per the wiki
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Brianmoooore
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The TPS uses a microswitch for idle and a simple leaf switch for WOT.
The WOT switch is so simple that it rarely gives trouble, but oil contamination, entering the TPS housing along the throttle shaft, can get inside the casing of the microswitch and prevent it from switching.
A drilled drain hole will allow the bulk of the oil to drain out, but spray cleaner will be required to flush the contamination out of the microswitch.
Because the microswitch is semi sealed, it may take a while to bring it back to life.
Note that when you refit the switch, it must be adjusted not just that the switch operates when the throttle is moved off its stop, but so that it operates when the throttle just moves off of its stop. Failure to do this will result in a flat spot when the car accelerates from closed throttle.
The WOT switch is so simple that it rarely gives trouble, but oil contamination, entering the TPS housing along the throttle shaft, can get inside the casing of the microswitch and prevent it from switching.
A drilled drain hole will allow the bulk of the oil to drain out, but spray cleaner will be required to flush the contamination out of the microswitch.
Because the microswitch is semi sealed, it may take a while to bring it back to life.
Note that when you refit the switch, it must be adjusted not just that the switch operates when the throttle is moved off its stop, but so that it operates when the throttle just moves off of its stop. Failure to do this will result in a flat spot when the car accelerates from closed throttle.
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tha881
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Many thanks Brian. I havnt removed the switch yet so will see if I can drill the hole without taking it off. What problems would it cause if the WOT switch wasn't working correctly?
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DanThe
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Its pins 1 & 2, and 2 & 3 that you should be testing
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tha881
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Tested it again today how you said and it's all good. Thanks