OK I was bored today so I decided to open up a TPS.....with my cheap $2.50 plexiglass cutter I opened up the back side of the TPS to see whats inside these trouble makers....If I was a dealer I would be ashamed to charge more then $15.00 for this hunk of plastic and brass

 

After looking these over I can see no-way for contact cleaner to get inside these TPS's because of the seal around the shaft so I drilled a 1/16 th hole thru the back side .283 from the bottom lip to be able shoot cleaner into the insides then resealed the hole with silicone

 

TPS- Throttle positioning sensor? I am a total newbie to the diesal lingo. With my 93- it had one of the early banks kits on it when I bought it- with the 98- 12v- I guess the sky is the limit!

 

I did a test drive with my trailer on because my tranny has been hunting petty badly lately.....this fix worked great no more tranny hunting and shifting was positive

 

Pappyman...thanks for the info. The first TPS that I bought was under $50. Then, the price went into the hundreds.
Guess they found out that they had a good thing going!

 

The electronic cleaner does make it in if you move the throttle while spraying.
I took one apart right after dousing it down once, I was almost shocked by how much cleaner was inside.

 

I tryed that before I opened this one up and after I had the back off......no cleaner got pass the blue o-ring seal around the shaft....maybe your seal was worn out and that allowed the cleaner to get inside....I tryed this on 3 TPS's that I had laying around I sprayed until the shaft area was full of cleaner then turned the shaft none of it got thru

 

Thank you, Thank you, I have been wanting to see inside of one of these!!!! Pappy have you took the wires out of the wiring harness from the pcm to the tps?? I did and it solved 99.9% of the problems I was having along with readjusting the voltage, but every now and then it will drop out of lock up so I was getting ready to make entry into my tps this weekend and now I know what to look for so Thanks again, I was wondering if a hole could be installed, now my question is with the hole in yours at the bottom would you just spray it full and let drain out and dry ?? Tell me more about this $2.50 cutter you used?? Thanks ,,,Rick

 

I just traced around the edge of the area that pappy removed with an X-Acto knife a few times then popped my cover off with a small screwdriver.

 

Like infidel said a X-Acto knife would work....I used a plex-glass cutter from Lowes or Home Depot that I like because it has a push and a pull cutting edge that really digs into plastic it cost $2.50.....I had my TPS off the truck then sprayed cleaner into the hole and worked the shaft and shook out the extra cleaner then I just dabbed on some silicone over the hole to seal it

I had 3 extra TPS's around so I took 2 of them apart....and as a test I drilled a hole in one of them that was in really bad shape when I replaced it it would make my tranny hunt constantly when I installed this test TPS it worked like a new one

 

that is the thing that causes all the problems. its just a potentiometer (adjustable resistor) the only thing that could mess up on one of those is the wipers not coming in contact with the brass ring or it was knocked out of alignment somehow

 

Has anyone tried to fill the things with dielectric grease? Would the grease interfere?

 

Die-electric grease shouldn't cause any problems....I don't think I would fill it but only coat it

I had to make a 300 mile trip last nite with my trailer loaded....using the problem TPS that I cleaned with contact cleaner and installed and it still worked like a new one....I did coat the plugin with die-electric grease.....later today I'm going to take the TPS wires outta the harness just to eliminate this possible problem too

 

It is a chore to get the factory ones out, I have the calloused fingers to prove it, the best way I could suggest outside of running two new wires is get yourself a dental tool with a curve in it and dull the point and work the wires out at 10 to 12 inches at a time,it takes some time but mine was really bad at unlock and lock and it solved it like I said earlier 99.9%,just tackle it like a pit bull and don't quit Thanks again for the very helpfull info,it will save a lot of money if everyone would apply the info gained here on this thread. Goodluck,,,Rick.

 

Took my old TPS apart today also . First when it was off I soaked it plenty from every direction , then worked it back and forth with a screwdriver . When it came apart it was dry inside . The right hand contact was corroded so bad it fell apart when I tried to clean it . By the way , those contacts just pull out with a tweezer for good cleaning . We ought to start a parts bin , bet we could salvage 90% of these SOB's