Engine/Transmission (1994 - 1998) faulty TPS

[mgause]

Yet another TPS question. Had my truck worked on last week and had engine steam cleaned. TC lockup has been flaky or non-operational since. Took off TPS and shot with contact cleaner and problem did not get better. Would it help to disconnect batteries to reset PCM? Or should I go with a new TPS, what is the best source for new TPS?

 

[JFaughn]

do a search here for TPS cleaning , I haven't done it yet but I've read here that some people are drilling a hole to clean and getting them to come back to life.

 

[WBusa]

Also, with age you will find your TPS, even after cleaning, can't get up to the 1. 0V output its supposed to have. Several threads here describe how to punch out the steel sleeves in the two mounting holes, then oval out the holes with a Dremel or such-like, re-mount the TPS loosely, then rotate it slightly till its back up to 1. 0 V output. Worked for me.

 

[Howard Durand]

Before you give up on the TPS, you can check it out with a good voltmeter. Unplug the connector to the TPS and run a real fine needle through the center wire. Re connect the plug and connect the voltmeter between the needle and ground. Turn on the ignition and you should read around 1. 0 volts at idle position. The test of the TPS is how it behaves as you advance the throttle. It should move up the scale smoothly to between 3 and 3. 5 volts. If it does this it is probably not your problem.

The fact that you had the engine steam cleaned would make me believe that you may have a bad ground or contaminated connection somewhere.

Steam cleaning removes crud and oil from metal and makes it more susceptible to rust. It also forces moisture into connectors that may be a bit leaky. Try removing the OD/TC connector at the transmission and spray it down with a water displacing electronic cleaner. Do the same with the connector at the TPS.

 

[CarlJensen]

Sounds like they blew some water into the TPS. Spraying it down may not clean it out as there is a water seal on the shaft of the unit. Steam cleaner has enough pressure to blow by it but not a spray can. Do a search on TPS cleaning and see how to open it up and clean it. Have holes in mine to allow cleaner to get in then I just seal up the holes with RTV until next cleaning. The wiper inside gets loaded with dirt and gives a flakey output voltage.

 

[SBozeman]

what is the best source for new TPS?

This site has reasonable prices on new OEM parts. I have seen a few show up on ebay also.