I keep killing TPSs... why??

(yes... another TPS thread. sorry...)

I swamped my XJ back in April. Replaced the TPS and it went bad around mid-May, and I replaced it. Today, my new one is going crazy, too. I'm watching the readings on my ScanGaugeII, and it's flucuating all over the place when I'm giving it steady pressure on the pedal (32% down to 16% up to 44% back to 32% then up to 99%), and bouncing from 1% to 17% with my foot completely off the gas pedal.

This is crazy... is it possible that I got two defective units, or could there be something wrong with my Jeep? I don't know how anything could affect a TPS besides extreme heat or water, and I haven't even been offroad since I installed the newest TPS. Is there anything specific in the wiring harness to look at? It doesn't make sense for the wiring to be fine for a month, act up until I replace a part, then be good for another month before acting up again.

Any suggestions?

Clean up all of your grounds and check out Ecomike"s thread "The Renx Files"!!!!

whatevah said:

I swamped my XJ back in April. Replaced the TPS and it went bad around mid-May, and I replaced it. Today, my new one is going crazy, too. I'm watching the readings on my ScanGaugeII, and it's flucuating all over the place when I'm giving it steady pressure on the pedal (32% down to 16% up to 44% back to 32% then up to 99%), and bouncing from 1% to 17% with my foot completely off the gas pedal.

Click to expand...

Are you having any drivability issues? My TPS will fluctuate a little when watching it on the Scangauge but it doesn't and has never caused any issues...

I just reread your %'s and mine only jumps 5-10% and only for a split second, so scratch that first part. I would go through and double check all your grounds and clean them up, maybe even run a few extra ones. You can never have too much ground.

http://www.greatlakesxj.com/tech/TPS.html

...and don't get it wet.

Try testing the TPS sensors loose, on the bench with an ohm meter. Hook the volt meter up to the TPS wires on the harness (No TPS), power on, engine off, and wiggle harness wires to see if the voltage changes!

check your grounds under the hood. specifically the firewall-to-cylinder head, battery-to-fenderwell, and the bunch that go to the fenderwell right under your ECM.

Checking your grounds after every run is a good Idea your frame and body bounce around alot. And sometimes things come loose. But you say you swmped it?

I would start with pulling the connecters to your TPS and making sure there is no water and or corrosion in side. The same goes for your ECM connections.

I work with steel day in and day out. And Ill tell you water is not good for steel.

All those little pins in the connecters could easily be corroded.

If they are go to your local parts store and pick up this stuff called PB Blaster, and spray it in the affected areas.


Adam