Really touchy TPS adjustment?

Back2Basics

Regular
Dec 30, 2005
317
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0
Milwaukee, WI
I attempted to adjust the TPS in the car and I was unsucessful so I took it out. I've got it on my desk here and its a lot easier to hold things in place, but the resistance readings arent the same.

The readings will jump very eratically. For example, this is how it goes....I'll turn it clockwise and it'll read a .03 > .09 > 1.60 > .12 > 2.60 > .04 > infinity. Its really touchy and it never wants to read a clean constant, or even go up evenly. I move it in small incrimints and as soon as I stop the reading lowers as I hold it there. I am using the needle style voltmeter so it is a bit difficult holding them on the sensor prongs, but it still seems like something is wrong.

Tomorrow I'm going to go get some alligator clips to help hold the testers in place. Any other tips in the mean time?
 

Kai

That Limey Bastard
Staff member
It could just need a good clean - sounds like the track and wiper is a little corroded, or just got years of carbon buildup. I'm sure someone can chime in with the necessary thing to clean it with - i'd say carb cleaner would do a good job though.
 

Back2Basics

Regular
Dec 30, 2005
317
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Milwaukee, WI
johnathan1 said:
I think you need a new TPS...

Any particular reason? It worked fine before I messed with it (no code 51). I only messed with it because I was desperate to fix my idle popping problem thats going on.

Everything is clean and corrosion free on the sensor and TB sides
 

Back2Basics

Regular
Dec 30, 2005
317
0
0
Milwaukee, WI
I know it makes sense what your saying, but I didnt throw any codes dealing with the tps. The bad idle is on when the engine is warm (already tested the ect sensor).

I just cant justify getting a new one yet as there are no related codes, no corrosion, and just the fact that it worked before. If you read my "Bad idle when warmed up" thread you can see that my idle issue couldnt be TPS related.

Edit: I figured out a way to hold the needle testors onto the prongs so I can better handle getting a reading. The problem is that its really touchy (ie. pushing the throttle lever down on the thickness gauge to get a correct reading, even touching the tb itself, or tightening/loosening the screws significantly effects the resistance).

Is anyone else's this sensetive?
 
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JesseH

Active Member
Nov 12, 2005
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Englewood, Ohio, United States
johnathan1 said:
I would get a new one reguardless...if it's old, it probably needs to be replaced anyway.
not always.......ive went through 4 of them trying to find one that works correctly, the one I got from tubbie a few weeks ago is also really touchy like that but after taking my time with it I got it calibrated perfectly fine. but dark006 if you do want to try a new one ive got one that calibrates fine, it wouldnt fit on my so thats why I have an extra one, the other two I have dont work. shoot me your part # and ill check if your interested.
 

JesseH

Active Member
Nov 12, 2005
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Englewood, Ohio, United States
Jeff Lange said:
I think johnathan1 meant to get a NEW one.
oh, i know.....but I dont think hes going to want to go out and buy a new one, I know advance sells a replacement for 170$....not sure about toyotas price. but if he doenst mind the price then I'd say go for it

EDIT: i would try kais idea of cleaning it and hit it with some CRC electrical contact cleaner thought before you get another one.
 

Back2Basics

Regular
Dec 30, 2005
317
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Milwaukee, WI
I dont think I'll be able to get a brand new one.

I cleaned up the contacts with some carb cleaner and a cotton swab. Still the same.

I pm'd you x87supra87x
 
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
The wiper and track will wear out after a while. Not much you can do at that point because the resistive film wears right through to backing. Our ECU will not throw a code when this happens.

PS Search for Volvo ETM if you want a real horror story about this problem.
 

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mkIIIman089

Supramania Contributor
Mar 30, 2005
3,061
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Ohio
I think he just needs to adjust it per the TSRM... instead of sitting there turning it and watching what one set of pins does.
 

Jeff Lange

Administrator
Staff member
Mar 29, 2005
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Sunnyvale, CA
jefflange.ca
x87SUPRA87x said:
oh, i know.....but I dont think hes going to want to go out and buy a new one, I know advance sells a replacement for 170$....not sure about toyotas price. but if he doenst mind the price then I'd say go for it

EDIT: i would try kais idea of cleaning it and hit it with some CRC electrical contact cleaner thought before you get another one.

New TPS from Jay Marks is $75.00.
 
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
Servicing the TPS wipers is not supported by Toyota, but you may be able to get some more life out of it by pulling it apart. Just make sure you have a backup plan if things go awry.

The telltale for worn wipers is a very noisy signal (resistance jumps erratically) between terminals VTA and E2 as the throttle is rotated.
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
Even though you seem to be another cheap owner who wonders why he has so many problems with the car I'll give it another shot.

First, the TPS is not serviceable by opening it. For one thing it's potted. If you open it you won't be able to get back together and even if you do it'll be in worse condition than it is now because the wipers are in the front half and the tracks are in the back. Second, it's unlikely to be the cause of your problem in the first place. If you want to know for sure short IDL and E together with the engine idling. Since VTA is not involved it doesn't even need to be connected.

Having said all that the TPS should be considered a wear item and replaced every 100K miles. They typically develop a flat spot around 25%-35% throttle. It's a thick film based resistive element on a ceramic substrate so unless you happen to have a plasma sputtering system with the proper targets in your garage there's nothing you can do to replace the worn film.

If you want to try cleaning it submerge in contact cleaner or alcohol for an hour. If you don't have either use vodka. Let it sit because the only path into it is around the shaft and let it drain afterwards. Don't expect much. The smart thing would be to buy a new one from the dealer or any car parts store. If you do a little searching you can get one for about $35.

Finally, if you're going to work on this car you need to buy a good meter and learn how to use it. Since one will cost more than a new TPS I doubt that's going to happen though.