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Stop me if you heard this one before

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Brando2120

New member
Well, last week I decided to finally change the leaking intake gaskets with the new aluminum wrapped gaskets from fel-pro. Before changing the gaskets, I decided that it would probably be best to clean the oil and coolant off the top of the manifold (as i didn't want it getting into my valvetrain). So I went to the local NAPA store bought some degreaser and sprayed it on. I waited 10 or 15 mins and washed it off with a low pressure garden hose. When I went to start it up, SUPRIZE, the engine revved up to about 3,000 and the SES light came on. I turned off the engine and waited about 30 mins. Went to start it again and it started normal, except for the check engine light was still on. When I went to drive it to the location I was going to replace the intake gaskets at, I was also suprised with the fact that it would NOT shift out of first gear. When I finally got to the garage, I hooked up the code scanner and it came back with a P0123 ( TPS high level input). I then back probed the TPS and found all levels ( referance voltage, ground, TPS signal) to be within spec. I have a feeling i have a stripped wire, somewhere. But my question is WHY WILL IT NOT SHIFT AND WHAT FRICKEN WIRE IS CAUSING THIS ISSUE. I left the car sit for a week now hoping that if some thing got wet that wasn't supposed to, it would dry out and all would be well. This was not the case. If you have any advice, or know of a thread that lists this problem your help would be greatly appriecated!!!
 
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your TPS may have unplugged, shorted, or you could have a loose wire.

find a PCM from a similar car and see if the code still comes up and if you can shift out of first. if your CEL goes away and your trans shifts, it's the PCM.
 
TPS is used by the pcm to shift etc. Pull the connector off the TPS and ensure it's dry inside. You are assuming a wire, but it could be the sensor itself etc. By cleaning the motor, you shouldn't have normally caused an issue like this... something was/is wrong that needs to be fixed.
 
Yes, I realize that the pcm uses TPS signal to signal a shift, but when I back probed the TPS all correct voltages were coming out of it. So it sounds to me like the signal is getting disrupted some where between the TPS and PCM.
 
check vac lines... my rubber T under snout came completely off and threw a TPS code. it did everything ur describing. crazy high rpms and trans wouldnt shift for ****.
 


Cost of new TPS: $60

Problems fixed: 0

The only thing new is now instead of a PO123(high level input) I get a
PO122(low level input)
 
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