TPS Replacement again after two weeks

[lndrvrxj]

Well awhile back i was having problems with the XJ not down shifting and shut off at low rpm's, i replaced the TPS sensor and everything went away. So here we are about two weeks later and everything is happening all over again, both of them started at the same time. Put the volt meter on it and it read 1.1 but it should read 5. Any ideas on what could be causing this to go out.
:confused1

88 pioneer

[martin]

Pay someone to examine the vehicle. You need someone who experienced with the Renix ignition system. It will be the cost of 1 hour of labor but that cheaper than a TPS. Also how did you set you TPS once you installed it? The multimeter method will do but the test set gives a much better result. It actually shows the value the computer uses.

Stop throwing parts at it. Call up your dealer, talk to the service dept, ask if anyone that worked there when your XJ was new. That how I found the dealer mechanic I use.

[lndrvrxj]

Well if at all possible i would like to keep the stealership out of it. So has anyone else had a problem like this.

[Arakele]

what kind of TPS are you buying that cost the same as a labor rate? rates in our area are like 60-80 bucks, more for dealerships. Did you try adjusting it any after i went inside last night craig? see ya later

[lndrvrxj]

I tried, but the meter just read the same. I don't know what to do, should i just think that it was a bad replacement sensor and get another or keep looking for other problems.

[Arakele]

dunno , need to get brian over here so we can test it on his jeep, sucks it wont work on mine

[martin]

Well dude you need to pay the $20 to Techauthority and buy the Electrical Troubleshooting manual for your 88 XJ. It is still available. With the manual in hand you will be able to see how your XJ is wired.

The first suspect is the grounds. You may want to remove the ground strap from the fire wall, clean the paint off and apply a coat of Ox-gard then reassemble.

Also there are grounds on the block. They attach to the same stud the dip stick uses. Remove the nut, clean up the terminals, apply oxgard and reassemble.

See if cleaning the grounds helps. Also with your volt meter check what voltage you are getting at different locations. But first suspect is grounds, then followed by a dirty connector.

You may still need to take it to a garage and have the Dealer tool or snap-on 2500 hooked up to see what values all the sensors are operating at.

[Arakele]

i'll call up rob and see if i can borrow his scan tool

[JBrobeck]

First thing I would look at is the ground for the TPS, that is a usual suspect for low input voltage. Most people Just splice in another ground to the existing TPS gound wire, and attach it to the cylinder head or firwall. Its a pretty simple and quick fix if thats the case. HTH.

Josh