Odin

1991 22RE

I tested my TPS and followed all the tests in the 93 FSM and it passed every one.

I left my multimeter (Fluke 12) in the ohms setting and hooked it up to terminals VTA E2.

I slowly turned the TPS from full closed to full open to look for dead spots and I have one at 4.0k Ohm's.

Is that normal? The manual doesn't mention anything about testing it during a continuous sweep like that but I had seen on 4crawler that any dead/infinity readings when doing that meant that it's bad.

Odin

I don't use a mutimeter much and it shows.

It wasn't an infinity reading it was my AUTO RANGING meter switching over.....
I guess this is part of why some people don't like auto rangers.

Derp

bswarm

A scope with recording ability will more accurately pick up a dead spot in a TPS. Using a multimeter works, just do the sweep very slow.

grumpin

First time I had that happen was very confusing!

bswarm

You could always stick a 10k ohm resistor between the TPS and one of the multimeter leads so it won't autorange. You're not looking for a value, just a break in the sweep.

wyoming9

iTrader: (1)

Look you can spend all kinds of time replace every part in the ignition system with Brand New Off the Shelf Toyota parts .

Then still have a annoying miss .

That is why I have far to many of these Trucks seeking the holy grail of one that runs perfect . well over $100,000.00 plus time .

I you think the TPS is bad get a new one I bought a few .

scope103

Dead spots (open or short, or even significant jumps) are not normal, and will cause problems. In theory you could take it apart and fix it, but I'd try a replacement. Particularly since you know how to test them.
Huh? If the meter is fancy enough to autorange, it's fancy enough so that you can turn it off. (I've attached page 6 of the Fluke 12 manual.)

(The Fluke 12 is a very good meter, but it's designed for "people who can't figure out how meters work." One with an actual range switch would suit your purposes better.)

bswarm

Not all autoranging multimeters have that. My Snap-On MT-145 doesn't, which is why I also have an old school analog swing needle multimeter. Still, a scope will show a glitchy TPS when a multimeter will miss it.

Odin

Yea, I got that Fluke meter back in about 93-95 and I think that's the third time I've used it to measure ohm's lol
I honestly haven't had many electrical problems and I don't work on cars that heavily like you guys scope/bswarm/wyoming. I consider you guys a big asset to this site
I was afraid a "friend" had lost my meter so I tried the Etekcity MSR-R500 from Amazon but didn't like it, the readings were all over the place just testing my spark plug wires and it had a cheap feel to it so I sent it back. I retrieved my meter the same day my Fluke showed up, go figure.

Thanks for the Vid bswarm. I thought that voice was familiar.. ScannerDanner.
I started watching some of his stuff last week. I watched him work on that 88 Ford F150 last night. Looked like he had a blast, poor guy lol
He's got some fancy diagnostic tools for sure. When he and EricTheCarGuy get together lol...
Now lets do it so the people who don't have all that fancy equipment will know how to figure it out lol, good stuff.
Eric's a bit crude but he gets it done.




I ended up taking the throttle body off and installing a used Denso TPS in damn near new condition because my old one was sending my meter all over the place compared to the new one.

Someone really cranked the throttle body down! I got both sides smooth to the touch with no gasket material remaining before I bolted it back together.
I didn't have my straight edge so I couldn't check the surfaces for highs and lows.
It looks like it's been running rich for some time, no sign of oil thank god.
It does look a bit black in the intake and I had to remove some build up on the throttle plate. It's strange to see that because when I installed new pugs I checked them a week later and didn't notice a bad rich mixture or fouling, it's been a few months though.

When I fired it back up it ran a little better. Now when I disconnect the TPS the engine slows down. The last time I did that with the old one the engine sped up.





A couple days ago I ran a propane torch around looking for a vacuum leak because I don't think the Idle Speed Adjusting Screw is responding correctly, I found nothing. This time I sprayed carb cleaner and everything was good except for the bottom of the throttle body. (I believe I didn't look there with the propane) I kinda expected it to leak in that area considering how much effort it took to break those bolts loose. I thought they were going to strip on me.

I hooked my vacuum gauge up to a source after the throttle blade and it was pulling about 17 hg by my gauge. It was only fluctuating about .50 hg so I don't think there's anything really wrong with the engine. I still don't have a tachometer hooked up so I don't know how high it was idling.

Just gotta get rid of that vacuum leak and set the valves. Then maybe tweak the mixture screw a bit IF it's all good.

wallytoo

iTrader: (1)

seems to be just like the one in my 87. the tps is set according to the 4crawler method, and checks in spec - except for the open reading on the multimeter while sweeping through the throttle positions. if i leave the throttle stable in any position, the reading is within spec. while moving through the range at anything other than a very gentle arc, the meter shows an "open". as soon as the the movement of the throttle plate stops, the meter reads correct.

it would seem that it isn't supposed to do that, yet i haven't found a definitive answer, and i hate throwing money at parts without diagnosis.

would someone with a functioning TPS be able to verify that the resistance reading, on the Vta-E2 terminals, DOESN'T drop out when sweeping through the range?

wally

wallytoo

iTrader: (1)

update: need to use an analog meter rather than a digital multi-meter when testing the resistance between Vta-E2 and operating the throttle through its range.

using the digital (auto-ranging), i had dead spots. using the analog, smooth, no dead spots.