TPS gone bad

[FatXJ]

I have never had the TPS go bad on me until today. I went wheelin and on the way back it started missing and sputtering and losing power. It got progessively worse until I could only do 20mph and 2000rpm max. So I checked the TPS and I got 4.6V In and 4.4V out. This means I need to adjust to TPS but there's one problem it's rotated all the way to the stops so I can't adjust it.

Is this what a normal bad TPS does? I have never heard a discussion on what happens when it goes bad on a testing level.

 

[Greg Smith]

If you have the auto tranny you input and output ration should be about 82%. Yours appears to be about 95%. If you can not rotate tps in either director enough to achieve the right % then I would replace the tps. Also check the connector to make sure they are clean and tight. Also check the c101 bulkhead connector (only on pre 89s). It is right above the engine toward drivers side. All sensors wires pass through this troublesome connector on way to computer. Often it gets corroded. Clean out old grease etc. and relube w. dielectric grease. Sounds like your tps is the primarly cause however given the % ratio. Greg

 

[FatXJ]

I recently cleaned the C101 connector searching for another electrical problem so that's not the prob. I had adjusted the TPS last summer after installing my header and it had 4.8v input so I adjusted it to 3.9v so i know it was right before. I think I might try to add another ground wire to see if that brings the input voltage up on the new one since spec is 5v.

 

[GSequoia]

Just a side note...careful with them guys...the snap ears on my stepper motor snapped off when i was doing an off mainfold TB cleaning...

All I gots to say is that the Zip Tie is my friend!

Oh, one more thing. Ditch the stupid potmetal scrwes that come with the TPS and use some good ones. The Torx heads have a way of rounding out if a Torx driver is withen 30 feet of it. (You might find that you have to grind the heads off)

 

[FatXJ]

Already done...

I put in a set of 7mm hex head bolts when I did my header.