edshred

1988 Toyota pickup, 4x4, no A/C. During my cleaning of the throttle body and air chamber I removed my throttle position sensor. The internal movement had plenty of tension and snapped back into position. Appeared to be fine. I lubed it with WD-40 and put it back on. I replaced the phillips screws with allen wrench screws (M4-7 metric size). I put the air chamber back on connected all air and water hoses. The throttle body went on next. All water and air hoses were connected. The air intake and Mass Air sensor were connected back onto the truck.

I start the truck. Idle is high.....I turn the throttle up about half way. The truck revs up then down, then up then down. This is weird....I let the throttle back down and it idles high but Ok.

I pull the wire connector off the TPS and rev the truck. The truck revs up correctly but seems sluggish and not quite right. This appears to indicated that the TPS is bad. So I head to Auto Zone for another TPS. Runs about $90.

I get back to the truck and install the new TPS into the truck. Everything gets put back together. I start the truck and the same problem persists. Could this be the Mass Air Flow sensor? I hope not that thing is bucks, about $200.

Let's take alook at the TPS. I manually rotate the sensor and check the settings. The old sensor is within specs but does not seem to connect to the throttle body correctly. I cannot turn the TPS enough to make the Ohms settings appear as the chart indicates. The throttle plate rotates with the TPS. This does not seem right.

The TPS was installed incorrectly. It appears that the small grooves in the TPS arms match up with the arms on the throttle body..... They don't. The arms on the throttle body go on the backside of the TPS grooves.
The below image indicates the gooves with the red arrow and the correct throttle body arm position indicated in yellow. This allows the TPS to be moved and the Ohms rating adjusted correctly.


If you move the TPS and the throttle plate opens, the TPS is on incorrectly. A simple thing brought the entire engine to its knees.

After the TPS was installed correctly and turned to match the Ohms settings on the chart. The old one worked fine. I returned the new one and used the money for beer......

Hope this helps save someone time trouble shooting.

Edshred

coooray

good catch, ill ha to keep that in mind when i pull mine off

trythis

If I touch my TPS and wiglle it slightly, the throttle plate moves just slighlty open and raises the idle some. When I say slighlty I mean piece of paper thickness. Is that the same thing? I think mine is probably bad but maybe it is on wrong. and I am checking it tomorrow.
THanks fo rhte tip.

edshred

I did not wiggle/rotate the TPS while the motor was running. But the throttle plate does not move while you twist the TPS if it is in correctly. The Ohms range moves quite a bit in the little movement area that the TPS allows.

My symptoms of a lagging throttle response seem to have improved. Just by setting the correct Ohm range. I have other issues as well. Hell the OEM motor has 218, 000 miles on it. It is finally starting to break in......

Doc279

EDSHRED

You just saved me $200.00 - thanks !
I bought an 85 last weekend and I knew from 4 crawlers site that the TPS
could cause throttle lag. When I cleaned and reinstalled the TPS - I did exactly like you - except I had not bought one yet. Read this and fixed my runner quick. Runs good with just a little lag between gears - I still think
the timings off.

Good Post Man !

trythis

I checked mine and it wouldnt set properly, so I took it off to find the spring would not snap back to 0. It would slowly rotate back within 3 degrees of 0 but unless I forced it, no go. New one completly fixed my sorry throttle response though, your tip really helped me install it properly.

edshred

It is posts like these that make you want to contribute. Thanks Guys!

We are in such a hurry these days. If all of us took the time and posted our experiences with troubleshooting and parts replacements. We would save countless hours running back and forth for parts and tools.

* Post what tools were used.
* Tool sizes
* lubricants used.
* Highlight hard items to remove.
* How much time was spent. Helps when the wife says "How long is this going to take?"
* Where you bought your parts and how much they cost. This alone saves hours....

EdShred *)*

thook

Thanks edshred,
I ran into this very same problem not two months ago when I bought a new TPS, OEM. After discovering I was putting the sensor on wrong, I put it back on correctly, but it didn't entirely fix my problem. The TPS still wouldn't register on an ohm or volt meter. After looking everything over, we discovered the tangs on the TB were bent out of place causing adjustment of the sensor to be impossible. We bent the tangs straight and now the TPS reads properly.

edshred

I installed a new TPS. On an 22RE. The used one I had for 18 months has gone out. Rough ideling up and down. Put the new one on (oreilys auto parts, $90.) and adjusted it to 480 Ohms between E2 and VTA. Lowered the idle to run around 900 rpms and I am working fine.

The next replacement is the Emissions hoses. Most hoses are still original. One thing that I have found is that a problem is not always blamed on one part. Most problems are a combination of parts that have degraded over time. When you replace one part the problem goes away. The problem or even another issue could pop up a few months later.

One part new, 50 more to go.

thook

Wow....double resurrection.

Hey edshred! This post should be stickied.

Chapman88SR5

whats this on a 22re or a 3.0? when i replaced one on a 22re i know i had to take the throttle body off but do you have to on the 3.0? also can you post what ohm settings yours is at if its a 3.0?

thook

It applies to both...as far as the correct installation. But, no...you don't have to remove the TB on the 3.0. Just need a short, short phillips head...stubby. I found one at Harbor Freight for about $.25 that's 1" long. Works perfect.

If you are interested, the ohm settings are in the FSM stickied on the forum's main page under "Links to FSM". It's the '93 service manual, but the specs are the same.
https://www.yotatech.com/forums/f116...umbers-102344/

MudHippy

Thread enhancements.

For the 22RE







For the 3VZE



These tests/checks can be done with the throttle body on or off the engine(both engines), and on 3VZE throttle bodies with or without vacuum actuated throttle openers(just skip that step if yours doesn't have one).

Chapman88SR5

did you guys use the thickness gauges because i do not have those

thook

I did. Mudhippy may have used his dentures, but I used feeler gauges. I just think they're more accurate. You'll have to get some...they're kinda neat.(I guess denture can be, too. But, brake cleaner doesn't work very well on 'em.)

MI-FL1+5

Hello new member here. Great Forum!!
1988 T4R DLX Auto 22RE. I have changed 2 new TPS and both have produced a very high idle. I have looked at all the detailed pictures I can find, and what I can find do not show any angle on these TPS receive tangs on the throttle body. They all look perpendicular to the center shaft of the throttle. These look bent to me, possibly to compensate for a TPS going bad? Any thoughts?

MI-FL1+5

I think I found my answer, anyone else experience this?
Originally Posted by @thook, might be my fix.
I ran into this very same problem not two months ago when I bought a new TPS, OEM. After discovering I was putting the sensor on wrong, I put it back on correctly, but it didn't entirely fix my problem. The TPS still wouldn't register on an ohm or volt meter. After looking everything over, we discovered the tangs on the TB were bent out of place causing adjustment of the sensor to be impossible. We bent the tangs straight and now the TPS reads properly.

GorgeRunner

Recent experience has taught me that a very small TPS adjustment can make a big difference in engine performance. The TPS does not need to test as defective to not work properly. Also, I don't think I would spray WD-40 into the sensor to clean it. Maybe electronic parts cleaner or in an emergency, brake parts cleaner. WD-40 leave an oily residue, the TPS is essentially an electronic component.