thook

Knowing the quality and care with which this motor was rebuilt, that's not a bad idea! Thanks

choppe777

I'm having the same troubles. While driving my 94 22RE Runner, the idle just dropped and it now stalls and runs really rough. I did a quicky tune-up and it's not really any better. Here's the weird thing...If I turn the ignition (to power the truck on, but not turn it over) it sounds like the fuel pump is running in my gas tank and I hear a little hissing behing the engine. What's going on??? Any ideas...or a good mechanic in San Francisco? ;-)

FYI- no check engine light (so I guess no codes) All the plugs were black (from driving it home when the idling problem started).

84sr5yoty

Uuuuhhh, the fuel pump cycles on when cranking and running only, so that means that either the fuel pump test connector is shorted or the AFM (air Flow Meter) is stuck in the open position. My guess is the AFM is the culprit. Check the flapper in the AFM and ohm it out.

choppe777

FYI- Mine turned out to be the faulty AFM (thanks 84sr5yoty).

Other items changed out that didn't help... plugs, wires, cap, rotor, pcv, fuel filter

thook

Congratulations choppe777!....I think. That's a chunk of change. :O

thook

Today...I'm going to just plug the hole where the temp sensor would be in the EGRV and see what happens.
I've had not much luck on locating the resistor to replace the sensor so I may then just bypass the EGR sys. all together. If anyone has a clue I'd appreciate it. Until then, I shall continue to dig. Thanks for all the input thus far!

thook

I found a sensor with harnesses from a '90 4runner today. The dealer says the part numbers are different from the '90 to my '92 and therefore the ECU wouldn't read the '90 sensor. Realizing this fellow has no hands-on knowledge...only what his book tells him...would anyone have some idea about this? The part is only $15 at the salv. yard. I'm hoping....

thook

bump!

TNRabbit

Don't know what to tell you there; if you bypass you'll have ECU issues.

Anyone?

suprathepeg

There was a period of change around 91 where some sensors, injectors etc were different. I would try byassing it by fooling the sensor, if that still leaves you with a CEL then find a sensor that matches the part number listed by the dealer for your runner. Toyota was pretty god with commonality of parts like sensors ie your sensor is likely found on other vehicles such as camrys and the like so you could do a search of the part number.

thook

TNRabbit,
I've been posting back and forth with a fellow with a '93 and he's had no problems.
Supra,
You are right about the changes. Dealer says '90-'91 are the same, and '92-'93 are the same, and continue to change after that.
Thanks for the tips. That had not occurred to me...and obviously anyone I've talked to around my area today.
I've called EVERY yard in the yellow pages, and there is ÅÅÅÅ for shine-ola on Toyota parts around here. You just can't hardly find 3vze's. Some yards won't part out things like sensors, and with others the motors, etc. are already gone. I really must live in some black hole where Toys-R-Not-Us! Anyway, to relieve my aching head I picked up the resistors today at Radio Shack after finding out what they are and where to get them. So, I'm going to make it easier and quicker on myself and install one....and plug the EGR. If it doesn't work, I'll know soon enough and I'm only out the $1.08 for a five-pack of resistors. Then I'll do some more digging around for a used sensor....following your suggestion, of course. Excellent tip!
You all...thanks so much for the input. Thumbs up!

TNRabbit

What resistors did you end up getting? I have no emissions testing and was thinking of bypassing the EGR altogether...

thook

Here is the link showing the resistors:
http://www.radioshack.com/product/in...entPage=search
Here is the thread in another forum where this is being discussed:
https://www.yotatech.com/forums/show...2&page=1&pp=25
I'll post my results when I get the chance to do the modification.

thook

The latest:
Okay, did the deed. I blocked off the EGR and the two vacuum lines leading from the EGRV to the vac mod. and the FPR (Was that necessary or a mistake?). And, I installed the resistor and pulled the codes...none, save the 41 because I hadn't put the TPS back on after testing it, once again. DER!! Well, sadly the vehicle stills run like poop! Hmmmm....
Getting back to the TPS.....when I tested it again last night the thing was out of position AGAIN!!!!! This is the third time. I'm very inclined to believe this brand new TPS is bad...and has been from the day I got it. It will not hold a consistent reading. When testing the first position (TVA and E2) the ohm reading was between .02 and .03....below range setting. So, I loosened it to reposition it and took another reading. The needle at this point would rise, drop back, rise again, and so on....it bounced all around. I even tested it again this morning. It was STEADY....although only at .03...again. I will do some reading, but does this sound familiar to anyone? I was quick to blame my meter at first, but it's steady as she goes reading other things. And with the probes in contact it stays bottomed out....a constant reading. So, unless someone tells me otherwise, I'm going to exchange the TPS for another new one and see where that gets me.
Just as well I bypassed the EGR because the valve was stuck...even after trying to clean it real well. But, I'm going to paint a big X on the seat of my pants if this TPS has part of my problem all along.

TNRabbit

Are the TPS adjustment screws staying tight?

thook

Oh yes, they are staying tight. The TPS itself is not moving, though. I've had the thing set by a mech., and three times by myself and the reading keeps changing. Say it's set at .08k ohms....next time I go to check it, say a day later, the reading then will be at .03k ohms. I don't get it....I assume, therefore, the sensor is bad. The said mech. had even suggested it could be bad. I will even call the dealer tech's today and see if they have any ideas on the matter.

rdharper

There are several posts in here about how you can put the TPS on such that it doesn't work correctly. Think you can find them with a search. Apparently it is a common problem.

Also, lots of people have thought their TPS was bad, and found it wasn't.

Last, have you tried running without the TPS connected? That little test seems to show whether the TPS is causing a problem. Specifically several people, including myself found that the truck initially ran better with the TPS disconnected. If so, you can assume the TPS is not helping, probably put in wrong, or still not adjusted correctly. Actually I ended up adjusting the TPS with the truck idling. Just found the point where the truck idled the same as with it disconnected, 800 rpm, then tightened down the screws. Not the approved method, but it was quick, and it worked.

Specifically, the adjustment is knife edge. It the idle position is not detected by the ECU, it will try to force the rpms down to 500rpm. If idle position is detected, it will idle at 800rpm, or wherever the idle is set with the TB idle adjust. So you set what the ECU "sees" by moving the TPS across that point, and tightening the TPS down where it just catches the higher RPM setting. That will be the ECU seeing the idle position on the TPS.

rdharper

After my somewhat long previous post, I had one more thought. Both the settings you measured in ohms, 30-80millohms, both will be detected as the idle position by the ECU. The threshold is way up there in Kohms, so the readings you are seeing are insignificantly different. It may be set correctly.

thook

If I'm thinking of the same problem you are, I believe it's where one hadn't set the tangs appropriately with the spring loaded return mechanism on the inside of the sensor body thereby not actually engaging the TPS. If so, then I became aware of that a while ago...discovered on my own purely by accident when trying to install this new sensor. In fact, I think I even posted on one thread discussing it.??? Anyway, that isn't part of the issue, but thanks for mentioning it. It was frustrating at the time.

Well, whether it's bad or not I already had Toyota put me down for a replacement. It should be in by Thurs. In the meantime.....

I've been screwing around with this thing for long enough now that I don't remember exactly if I tried adjusting while the motor was running. I know haven't tried disconnecting it to see where that got me. So, I will try it, but after all I've read this sensor seems rather important for several things. Specifically, 4crawler's page on TPS adjustment and troubleshooting. Apparently, it worked for you and others, so I'm certainly not against trying it. I've got nothing to lose at this point...hopefully! Did you happen to have the benefit of a hand held tac meter? I don't, and that was recommended for accuracy on idle rpm. I will see what I can do with the tac on the instrument panel.

It took me a few minutes to grock what you are saying about the ECU and "what it sees", but I'm fairly confident I understand. Thank you for that tip!!! I don't recall having read that bit of info anywhere. Then, I could be wrong.

Admittedly, I'm still not expert on reading an ohm meter, so after reading your last post here I realized I relayed my readings incorrectly. The settings I used as example should actually be read as 3 ohms and 8 ohms. My meter goes only to 1k. It's a little ol' thing! The thing is, it jumps right from 200 to 1k right at the end of the upper range.?? Anyway, the values for the TPS the online FSM (posted earlier in this thread) specificies is 0.47-6.1k O. between VTA and E2 terminals. Is the meter I have sufficient for the job? 4crawler's page says the 20k range is ideal for a meter, but don't the values still convert within whatever range your meter uses? Confusion means one still does not understand. But, I'm trying... On that note I'm off to read and do some tinkering. Maybe, I can get my hands on a better ohm meter.

Thanks so much for your input. It helps alot!

rdharper

Thook;

This link may have been posted earlier, but just in case, it contains just about all you need to know about the TPS, including a mini-course on ohmeters.

http://www.4crawler.com/4x4/CheapTri...l#ThrottleBody

Personally, I prefer an inexpensive radio-shack type 3-4 digit lcd with a replaceable battery of an AA, or AAA type. Very cheap these days, you can get a good one for 25-50 bucks.

Note that the picture of the TPS showing E1, IDL, VTA, and VCC is a bit confusing, as you are looking through the cover, so E1 appears at the bottom. This is at the top on the V6 TPS as it is positioned insitu.

Since you are buying a new one anyway, you can check it against the chart in that link, and understand how it works.

There are essentially two things going on, the off-on switch which tells the ECM that the throttle is physically at the idle position, or not. This corresponds to the <2.3kohm case, which my own (both of the two I've checked) shows in the 10ohm region. This jumps to greater than 2. 3kohm and should read open or infinite as you twist the TPS against its spring. Think of it as a switch, with a knife edge. This should be just set to indicate idle at the idle position, or the low ohm reading.

The other thing going on is the linear throttle position, so-called wide open position. It should be about 200-800 ohms at the idle position, and should show a linear range above that. Theoretically you could have correct settings and correct reading for both at physical idle position, and still have some kind of non-linear intermittant condition in the so-called wide-open range. That is hard to check for with an ohmeter.

As far as I know, most of the problems people are having with the TPS are related to the setting of the idle "switch" position, either misadjusted, or installed incorrectly. There are several write-ups on that. Its a bit tricky to install it on the V6, as there is not a lot of finger room, or screw driver room, hence the suggestions for replacing the screws with a hex type screws. I was able to glue just the right phillips bit into a 1/4" box wrench which works almost as well.

I also got the plug-in connector with the color coded wires to make it easy to check the TPS while in position. But in the end, after verifying the TPS as functioning correctly, I made the adjustment with the screws loosened enough to just grip and hold position, while the engine was idling. The idle position gave me 1200rpm, the open position 500rpm. I set it so that the 1200rpm was just barely engaged with the throttle in the physical idle position, and tightened the screws. Then I brought the idle down to 800rpm with the TB idle adjust. That makes sense if you get how the thing works, and how the ECM is programmed for the TPS.

This worked for me. If one has to go by the book, you could disconnect the TPS, and recheck the new settings with an ohmmeter. But I didn't as it was now giving good performance, and smooth idling. Quit while I'm ahead.