ToyYoda

That best describes what this 4runner is doing that I'm planning to buy. I haven't gotten it home to really look into the problem but I wanted to run it by you guys so I can make a list of things to start checking for right away.

First of all, the truck has been sitting for a year. It started great and has had a recent partial tune up. It idles good but when I tried to accelerate it would sputter and then after a few seconds of it sputtering, it would just take off like I hit a 150 shot of nitrous and accelerate smoothly. It only sputters when trying to get going from a slow speed, then, once it gets to about 2k RPM, it clears out.

Any suggestions or easy fixes for this problem?

scuba

i would have no clue...
and sorry for the hijack
but i noticed your in austin
im not very adventurous
but i would love to get my truck out on some trails
any between you and me thats worth checking out ??
*that you know of*

thook

Sounds like a dead zone on the TPS......VTA track/throttle angle. Put on ohm meter to the TPS on the VTA and E2 (neg. probe on E2) and move the throttle plate slowly to wide open and back again. The numerical reading should increase and decrease smoothly. Not drop outs or erratic behavior.

Example: from one on up to ten.....not 1,2,3,4,5,3,4,5,6....10.

Follow?

Illustration for TPS terminals:
http://personal.utulsa.edu/~nathan-b...34throttle.pdf

ToyYoda

Ok, so I found out that after the engine warms up the problem goes away and it runs great. Maybe the water temp. sensor/timer needs to be cleaned? It sounds like a misfire when it's cold but only under load, like it has too much fuel in the cylinders.

thook

Timing switch....no. That's only functional for a second or two when you cold start. But, the water temp sensor is a definite possibility. I've had luck cleaning them before.

Racer944

Sounds to me like something to do with the fuel delivery. Sounds like it's running too rich. I'm exhausted right now, but that's my first guess.

ToyYoda

So the problem doesn't go away when the engine gets warm, the problem just gets better faster but I have to drive it to get the sputter to calm down but when cruising the truck, it bucks around a little bit like there is a misfire. I tried to short the timing jumper or at least what I thought was the timing jumper, it is in the right spot but not the same as my other 22RE's and got a blinking check engine light and the engine didn't idle down, nor was I able to check timing. The TPS is where it should be. The CAT has already been gutted as well. I'll check the spark plugs next and see what they look like.

94svt50

I have a very similar problem, when I checked my plugs I found them to be white and glazed over, very lean. Just mounted a fuel pressure guage to see whats going on, so far inconclusive. Things I have already checked. Changed out fuel filter and AFM also checked TPS, cold start injector, coil, pickup coil, coolant temp sensor, EGR and looked everything over for vacuum leaks. Keep us posted if you figure it out.
thanks-jon

linuxrunner

My truck did the EXACT same thing when I first got it...

Turned out to be a bad TPS and a bad o2 sensor. Replaced and i was good to go, but i had to drive it on the freeway a few times before I was able to get the parts and it was scary. No acceleration and going like 5 mph with peddle all the way to the floor... then all of a sudden WAM takes off like a mad man.

de6w6it

I have the same issue, but it only happens when I drive on a wet road, and for the day after that, until I can only guess, it dries out. It does it at all throttle positions, except if I put it all the way to the floor, it runs smooth. I have replaced plugs, wires, cap, rotor, all new vaccuum lines, battery cables, the O2 sensor is relatively new, afm, ecu, tps, all new exhaust, blocked off egr, and still the same issue. i have no codes when i short the diagnostic terminals. I think I am going to try and throw in a new O2 sensor, because I have really exhausted all other ideas. let me know what you find, I will do the same.

toyotatom93

I had a similar issue and changing the plugs fixed it...try the easy stuff first.

Greg_Canada

If it's the TPS, it probably just needs adjusting. Check roger brown's site www.4crawler.com for tuning/readjusting your TPS.

ToyYoda

I've gone through adjusting the TPS already. They had replaced the spark plugs and wires 2 days before I bought it. I have a fuel filter to replace but the one in there looks like it's been replaced recently. Could bad gas cause this problem? If it was bad gas I would think it wouldn't run at all.

The timing jumper says X and has a black wire seal instead of having a T on it and being white? Is that the same thing? jumping it does cause the CEL to blink but seems like it's displaying CEL codes and not doing anything with stopping the advance of the timing.

94svt50

Just wondering what brand and how old you O2 sensor is? I have the Bosch brand type that splices in, and from what I read this does not work well with toyotas. Im begining to suspect that is what is causing my problem, which is identical to what yours is doing. Thinking about plopping down the$133 for the OEM Denso brand O2.

thook

Listen....the TPS could be correctly adjusted and pass all the tests in the FSM, but still fail a throttle angle "sweep" test. I found that mine was bad that way. It may not be your problem, but it does sound like it.

Read this thread....specifically the dialogue between myself and 4crawler. Of course, skip whatever doesn't apply.
https://www.yotatech.com/forums/f116...or-cel-129413/

BTW, what year 22re is this?

thook

I've been using a Bosch in both my 4rnr's without issue. I don't know how to explain the discrepancy, though.

thook

Uh....I just remembered, you could always unhook the TPS and drive it. Others have found that with a bad TPS that the vehicle initially runs better. Bypass the TPS input to the ECU, and within a short time the ECU compensates by default. It'll throw a code, but don't worry about that. Just reset the ECU after the testing. If it runs better, you'll know the TPS is a factor and then you can run any more definitive testing if you want.

94svt50

While the problem was actually occurring I unpluged the TPS, it revved up a bit but, the problem still stayed the same.

ToyYoda

It's an 86' 22RE. I unplugged the TPS and got no change, not even a check engine light...at least not yet.

Now that I've been messing with it, it goes away faster than it did but always does it after it's been turned off and sitting briefly. When I first start it, it doesn't misfire but it does do the nitrous feeling, then maybe a minute later it will sputter for a few minutes and eventually it goes away enough to where I can at least drive it normally and the idle will be higher than when it's misfiring badly. I plugged a few vacuum leaks and replaced some fuses, so the truck is getting there. This problem is so strange. Sometimes I really hate EFI but when it works, it's great!

The #1 cylinder plug looked perfect. I'll check the rest tomorrow.

iamsuperbleeder

Ah, same issue here, and it's driving me nuts. But I'm pretty sure of the reason in my case. Mine only started doing this after I had water over the hood and sucked some muddy water into the AFM (K'N filters filter air great, but not so much water, lol). I tried to clean it and dry it out to the best I could, but about a day later while driving it, I started noticing the same symptoms you guys are; starts fine, and actually runs fine on first startup and running, but if you let it warm up, shut it off, then start it again a bit later, it'll run fine for a bit, then when you try to go anywhere, under partial throttle it spits and sputters and has no power until about 2,500-3,000 RPM, and them WHAM, it's like horrible turbo lag, lol. Under full throttle, it runs fine though. In my case, I'm pretty sure my AFM is toast, and it's been burning a lot more gas than it did before, so it's been running rich too. This all happened about 4 months ago, so it's been running rich for that long and I've just been dealing with it. Chances are my O2 sensor is shot now because of the rich running, but I'm replacing that with the exhaust upgrade soon anyway. Not until I put in a good working AFM, which is on it's way right now (I love eBay). Both of these parts are the originals as far as I can tell, and if that's the case, they have 284k miles on them, lol. I'll let you guys know how it woks out; if it helps at all.