RobbyP33

Recently changed out the emissions harness and tps on my 87 n/a. I go to adjust the TPS and its reading two volts and its not changing when I adjust the screw. Does anyone know whats going on?

RobbyP33

It was reading 4 volts then it fell to 2.14 randomly.

satch

iTrader: (1)

Which wire color and was the engine as hot as it possibly could get?

RobbyP33

I was on the green/red and i think so but not sure, my temp sensor is broken.

satch

iTrader: (1)

What does the temp sensor have to do with it. Getting back to the TPS, it needs to be measured as stated above. And if you press down on the screwdriver when setting it the voltage will increase.

Fritz Flynn

iTrader: (263)

I just replaced a TPS in one of my cars that was reading 4 volts at idle and wouldn't change much after adj. Swapped it and adj to the normal .70 or so. This was for an FD.

I think your sensor is bad.

RobbyP33

Temp gauge my bad, i mean im not sure if the motor was warmed up all the way.

RobbyP33

Got a new temp gauge and warmed engine all the way up. Its reading around 4.13 volts. Is it safe to say i need a new tps?

lduley

iTrader: (1)

You need to drive the car for about 20 mins than adjust it

RobbyP33

I did that it still reads 4.13 volts

satch

iTrader: (1)

If it reads over 4 volts w/the engine idling at an acceptable rpm then chances are you need to replace the sensor. The other two wires should read 0 volts (ground wire) and the Vref would read 5 volts, both tested w/the key to on. W/the engine off,key to on and engine fully warmed the sensor should read close to 4.5 volts fully extended and about 1 volt when the piston of the TPS is receded almost all the way (but not completely receded/hidden within the sensor). And finally make sure the sensor plug is snugly connected to the emission harness.

RobbyP33

What do you mean when you stay the plug is hiddin within the sensor?

satch

iTrader: (1)

I didn't. I stated something about the piston/plunger being recessed within the TPS.

RobbyP33

Where is the piston?

satch

iTrader: (1)

You know that round column looking thing which comes out of the TPS. I mean there are only so many parts to the TPS and only one part which moves.

RobbyP33

Yes I know what youre talking about. That part moved before I even put it on the car. Is that supposed to happen?

satch

iTrader: (1)

Is what supposed to happen?

RobbyP33

Is the part supposed to be loose and turn, because i dont think my previous TPS did that

satch

iTrader: (1)

It's supposed to extend and recede as in doing that it sends a signal to the ECU. If you wanted to you can rotate it but that changes nothing w/respect to the signal it outputs and it doesn't rotate when in use.

RobbyP33

I checked it today while I was putting in an AC belt and it does extend and recede. I do have a working TPS (was the old one) but it dosent have the 3 prong connector to match the harness, do you know where i can find just the connector?

satch

iTrader: (1)

Use the one off the TPS which is in need of replacement.

RobbyP33

I dont want to do that because then i can return the broken TPS

satch

iTrader: (1)

Then you'll have to pull one off a junk yard car if you could find one or purchase a used one on the cheap and remove its plug.