jennygirl

My TPS was binding up a bit, and after lubing it (per the suggestion of a friend) the electrical contacts seemed to be acting erratically.

Rather than toss it in the trash as they then suggested, I decided to say what the heck and crack the sucker open to see what could be done.





As you can see there was a good deal of crud around the tracks. I blasted it with some electric cleaner, put the teensiest dots of dielectric grease on the 4 terminal like things and sealed it back together with some silicone sealant.





Tested perfectly during calibration, and now my car runs better than before

The definitive TPS installation / calibration procedure can be found here:
http://4crawler.com/4x4/CheapTricks/TPS/index.shtml

Never put a TPS on a throttle body without calibrating it. It takes a lot of finesse to get it right. If you just slap it back together, your car will run like crap. We are talking fractions of a millimeter!

I hope this helps people having TPS issues. The symptoms can be very frustrating. Trust me, I know!

rworegon

Nice job! Good info.

Hugh_Mann

Woah, sweet. I was too chicken to open mine up, thought for sure I would break it. A Local auto wrecker provided a working unit at a fair price instead. I'll keep this in mind for my old one in case I end up needing it again!

jennygirl

Yeah I too almost fell victim to thinking it was some finely tuned electrical piece. I mean the calibration is very fine-tune style, so I figured the actual piece had to be the same. Turns out it's very simple!

I would recommend putting a piece of electrical tape over the back of the internal contacts before resealing. I just realized I may have gotten lucky.

Hugh_Mann

I won't lie. The way you gooped it on there made me a little nervous, hahah!

anndel

Just out of curiosity, that's not the vinegary silicone sealant correct? If so, vinegar emits acetic acid and will corrode those contacts. They say not to use vinegar smelling silicone with electronics since it will corrode contacts and electronic components.

jennygirl

It was a black marine silicone (all that I could find in the garage).

If it starts acting weird or if I get a CEL, I'll post it. Just went on a short errand with some friends and everything seemed great so far! The real kicker will be engine heat over time, I think. Prolly will use RTV if I have to do it again.

jgranthevagrant

for the amount of time to pull it, clean it, and re-install, re-calibrate, it was worth it for me to install a new one. Mine was 24 years old. I took the old one apart, and it was way beyond rehab.

Terrys87

iTrader: (1)

Great write up. You are correct on getting it set is a real pain. I have one that is acting up that I want to try this on.

jennygirl

Cool! Let me know when you do and post pics of how you reseal, I am curious if you will do it differently

wyoming9

iTrader: (1)

I think you next project should be rebuilding ECU`s that no longer work.

You take such great pictures.

jennygirl

HA! That would require my ECU to fail, then you can definitely bet I would be cracking it open before tossing.

A few months ago I helped a roommate fix his 87 GMC truck ECU. The previous owner had installed a higher amp fuse and his ECU ended up going pop when he accidentally reversed the battery polarity- dingbat! We opened it up and found a fried rectifier diode on the main board. I desoldered it and replaced it with a spare... it worked!

I have a feeling yota ECUs are a similar makeup.. Looks like they are soldered by hand, meaning usually they can be fixed by hand.

I'm glad you like my pictures Thanks for saying that!

jennygirl

Small update, I noticed my sealant cracked after 5 months (probably due to temperature changes and vibration is my guess). I will use a better sealant next time.. Probably the black gasket maker stuff from toyota. I'm also open to suggestion

I refuse to buy another TPS!!

Odin

Sounds stupid but I've read that GE Clear Kitchen and Bath Caulk actually works pretty good. ???

jbtvt

Despite all the shoutouts I give their products I'm really not a Dow corning rep. Their 795 sealant - - is the best all purpose sealant you can buy. Decades of full sun on exposed glass can't kill it, and with 50% joint movement it will never crack. Most neutral-cure silicones will perform similarly. With any sealant it's important to wipe clean the substrate with the correct solvent before applying.

88xtra4x4

Good writeup about cleaning it. One of the best things I ever did was replaced mine with a new unit and replacing the screws with allen head cap bolts. It makes it super easy to adjust and torque down.

I have used the rtv on my VAF (toyota's version of the MAF) sensor when I cleaned it up and had to reseal it.

Odin

That sounds promising.