I know there are a million TPS threads but I havent found anyone with my problem.

1990, 5.0, 5 speed

Surging idle, no codes

TPS voltage:
Green wire, 4.99V
Black wire, 4.99V
Doesnt change with throttle position

Has anyone run accross this before? Thanks.

 

its dead. replace it. it has an open short inside of it.

 

That's what I thought, so I replaced it, same problem

 

Hi,

Do a voltage drop test on the feed side and the ground side of the TPS circuit and let us know the results.

Im ASSuming you did try to sweep test the old and new TPS correct?

 

the black is the ground side iirc..if you have voltage on tha side there is a short somewhere on that side

 

probably testing it wrong...

ground the black probe to a piece of metal on the engine, then probe each wire with the red probe individually...

 

I put pins in both the green and black wires. First checked the voltage accross the two and it was zero (gunna go back tonight and check resistance between the two to see if they are shorted together). Grounding my black probe to the battery and probing with the red lead, the green wire and black wire both showed 4.99V.

 

You should have a fault code with what you are describing. Are you sure you pulled codes correctly?

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