4runner_keith

Ok so about every mabey 200 miles or so ill be driveing down the hwy. Then just about as quick as you can blink or mabey even snap your fingers, my cel will flash just once (boom) then gone. And when it does happen my Rpm's drop down like my engins choken or something? But as quick as it came on then, bam gone??? I'm stumped! any input on this problem? It's a 3.0 with 169,000miles

scope103

Use the special tool (paper clip) in the diagnostic connector to check for STORED codes.

Sudden drop in rpm COULD be a problem with the knock sensor; when it detects knocking, it retards the timing to save your pistons, which would manifest as a "choke." The suddenness of the change is inconsistent with a knock sensor problem, but that's why you check for codes.

yotasavg

I have the same problem! And miles! I've checked my codes and have found nothing.

MudHippy

It sounds just like the code 11 problem that the older 3VZEs would have. I've been having that issue with mine, an 88, for a couple or more years off and on.

Basically, it will act in the exact same manner as described. The only difference is that the check engine light will sometimes stay on for a little while afterwards or untill I turn the ignition to the off position. It always triggers a code 11 when it acts up like that though. That code is no longer existent on the later models, though how long after 88 it was before it was discontinued is unknown to me. I believe it's only on the 88-89 3VZEs though.

Code 11 = Momentary power loss to the ECU

However, since what's believed to be the root cause of the code 11 issue is still applicable to the later engines, the issue could hypothetically be of similar origin. What's believed to be the cause is the signal from the VSS(vehicle speed sensor), or rather lack there of. The ECU will become confused when it sees a disturbance in the signal from the VSS and will refuse to send the signal to the injectors to fire because of this "noise"/interference in the VSS signal. It will actually briefly cut the power to the fuel injectors thinking that the vehicle has reached the top speed allowable, or it's top speed governor set point.

Having said all this, I still remain highly suspicious as to the real cause of the problem. I've tested my VSS and it appears to be in perfect working order. Which only means it might not be at fault. So I still have no real clue what's going on with mine. And NO, there doesn't appear to be any shorts in any of the wiring leading to or from the ECU. I've checked every possible culprit and haven't found anything that could be at fault.

Aside from replacing the ECU, which has been done by another member here and didn't solve the problem, or replacing the speedo/odo/VSS unit in the combo meter(VERY SPENDY!), I don't know what to do about it.

Here's a thread that explains it more thoroughly.
https://www.yotatech.com/forums/f116...e-nuts-186678/

Definitely read this article on the matter too.
http://www.motor.com/article.asp?article_ID=271

e6rock

Hello, did you ever find out what your problem was 4runner_kieth? I have a 91 3vze that has the exact same problem. cel flash and quick rpm drop randomly while driving. The truck recovers almost instantly. I know this is and old thread, but any help would be greatly appreciated! I have read the highlighted thread at the bottom and think it could also be the VSS?

MudHippy

Replacing the distributor fixed it for me. I replaced the cap and rotor first. Which seemed to make a difference....briefly. It was better for like a day or two, then started doing it again. I figured since that was the only thing that appeared to have mad any difference at all, maybe the distributor itself had something to do with it(even though it passed inspection, aside from some end play in the shaft). Call it luck or call it a cure. But my truck doesn't do it anymore with the new distributor.

94yodasr5

Same thing here I have a '94 pickup with the 3.0 new cap and plugs took care of the problem.

e6rock

thank you, I think i will replace the distiributor. I recently did HG and top end rebuild and this "hiccup" is the only problem on the truck now. Passed smog with flying colors though... Great help guys! i will post if it fixes the problem.

az4x4runner

Reviving this old thread again...

I have a freshly installed reman 3VZE that just did this exact thing. Plugs are new, distributor cap and rotor new, only about 120 miles on it since the engine was dropped in. No codes.

Any luck with the distributor? Or any other findings? This seems to be the only thread on YT describing this issue .