DeWolf

My 86 TPS is full of oil, or was, can i just spray it clean with WD40 or similiar, or, is it a replacement job?

Crumpler

Most of them are by now.
You can check ohms resistance for idle switch and wot switch at LH plug to see if still on spec.
That said, I would still clean it.
Regards
Dave.

The Forgotten On

There are small o rings in the throttle body that no one ever replaces. This thread goes in depth with its replacement as that will leak oil into the TPS and cause a vacuum leak.

https://rennlist.com/forums/928-foru...-there-is.html

If it is within spec after getting oil filled I would still replace it so you don't have to worry about it again in the future.

Hilton

They're not o-rings, at least on the S4 throttle body - they're actually very small lip seals. I bought some o-rings before taking one apart a few years ago.. discovered when I pulled the rubber out that they were seals.

It might be possible to replace just the seals - I haven't actually tried to measure and source the seal separately - I just replaced the bearings as a unit.

Landseer

Roger I think has a solution to this. We all got into it a few years ago when Mike Frye did a write-up on 85/6 intake refresh. Dwayne also addressed this somehow in his S4 intake refresh writeup. I forget exactly where we all ended-up, will try to search it for you. Sounds like Hilton has most of the answer.

Bill Ball had discovered that his TPS had damage that was hidden, I think a cracked place in the metal contact spring thingy beneath the plastic. There are some posts / pics from the 2004/5/6 timeframe IIRC where he recorded his trials and tribulations over this.

I've taken a few apart, all with oil, but all seemingly working ok when metered. I thought the tps had orings itself, but maybe not. Yes, just cleaned them with WD, which is mainly mineral spirits, reassembled, no issues for mine. I think I messed with trying to manipulate the WOT trigger by bending the contacts to no reasonable solution.
Relevant threads I saved:

https://rennlist.com/forums/928-foru...le-switch.html


https://rennlist.com/forums/928-foru...-there-is.html

Crumpler

+1 on all the above posts.

My TPS was actually not in spec for the WOT switch anymore and I replaced, but I was really chasing down what turned into a computer problem at the time. I wasn't doing an entire intake refresh -- just chasing my tail, so I would love to get the definitive Roger solution before I take that project on.

Hilton

I bought my bearings from a local Aussie bearing supplier (http://www.conbear.com/ - CBC Bearings). I got the same as the original - HK1012RS.

From memory, Roger sells a more robust version with a seal on both ends, so not only does it hold vacuum in the throttle body, it also protects the bearing from ingress of dirt from the other side too.