ec-williams

i have had my 88 4runner with the 3VZE for years and about 2 years ago i had a code 11 pop up. (momentary power loss to ECU) I have changed the ecu and that did nothing. The dealership said they cant find the problem till it completely breaks down. (cool, right) the truck starts fine, and accelerates fine. however, when the rpm's hit 2300rpm it will cut out out to 2000rpm, then go back up to 2300 and do it again, so it flutters. if i gas it, i can go right past 2300 to higher rpms and speeds. its just when Im in town it will flutter, it sucks! I've been going back to school so money is tight, so i would like to fix it myself, the truck has been parked for the last 2 years, but still starts and runs. i miss her... i love my truck and would love to go get some mud on it... has anyone had this problem, and know of a solution. or know of anyways to fix or narrow down the problem, without just buying new parts at random....

someone please help me

Tubbyfatty

Have you torn apart the dash and followed the wires or just looked for a break somewhere in it?

That would be where id start first. Just take your time and look for either a bad ground, crappy connection or a wire that has exposed wires.

Oh yea, Welcome to this amazing site! Throw your rig in your signature. user cp, edit sig. for future reference.

myyota

I don`t know anything about the 3VZE engine, but on a 22RE a code 11 is usually the TPS, I don`t know if that would be the same for your engine, but it might be worth checking out.

TNRabbit

the 1993 FSM doesn't list a code 11....??

sb5walker

I don't have an 88 4runner manual, but if code 11 is intermittent ecu power drop and a new ecu didn't fix it, then there must actually be a problem with ecu power. I would start there. The efi main relay would be my first suspect - try a known good one of those, and make sure the socket terminals are clean. If that doesn't fix it, it may be a problem with the ignition switch.

As far as the motor's strange stumble issue, does it only happen while driving? On older 4runners/pickups the vehicle speed sensor (vss) is a mechanical reed switch in the speedo, and when it gets old the signal can get noisy, which is interpreted by the ecu as excessive speed and so it activates the governor feature. Not sure if that could cause your issue, but it's worth a look. Here's a tech article on the issue:
http://www.motor.com/article.asp?article_ID=271

And some info on finding the vss wire: http://www.the12volt.com/installbay/...TID~98493~PN~1

A few other thoughts - check the resistance of the signal coils in the distrib, as well as the rotor gaps, and make sure the connections between the distrib and ecu, and igniter and ecu are sound. Also check the igniter ground. If IGF from the igniter to ecu is interrupted, that will cause the ecu to stop firing the injectors.

Verify the E2 (engine) ground, and the E1 (chassis) ground - see the vehicle wiring diagram for the locations. E1 is usually drivers side post, and E2 grounds through the ECU to the engine somewhere. On my 89 pickup I think E2 grounds through E01/E02. Make sure the grounds have good, solid connections. I usually remove the connection, clean it up and reattach.

Otherwise, I would reference the troubleshooting section of your vehicle's fsm and start checking voltages at the ecu terminals. If you don't have backprobe leads for your multimeter you can use sewing needles and press the test leads against those.

MudHippy

Well, well, well....so it's not just me having this annoying code 11 problem! Momentary power loss to ECU is correct diagnosis(I don't know exactly when/why after 88 it disappeared from the list of codes for this engine). My 88 3VZE has been acting in exactly the same manner as you've described for around the last 2-3 years. The "semi-stalling" or "hiccup" seems to occur very sporadically, sometimes it goes away for a month or so, sometimes it happens several times a day. But even when it happens so subtly that I don't notice the behaviour as I'm driving(only happens when driving), the code will still be present incessantly. I had all but given up on trying to alleviate it....'til now!!!!! WE CAN DO THIS!!!!!!

I replaced my EFI main relay(with a brand new one)and it made no difference. So I suspect that isn't what's causing mine to lose power momentarily.

As I said, it only happens when I'm driving. So I'm very interested in the possibility of the VSS being at fault. That would be the only thing you've suggested that I haven't already checked, checked, and rechecked more times than I can count. I didn't even know such a thing existed, and I THANK YOU VERY MUCH for bringing that to the table. I feel I already owe a HUGE debt of gratitude. I have been waiting for the solution, or at least a logical explanation of this for quite some time.

Thanks again!

sb5walker

Happy to help - though, to be fair, it was desconhecido who brought the issue and the tech article to my attention several months ago - so the thanks go to this great yotatech community.

(Now we just hope that's what's causing your trouble, lol.)

ec-williams

wow, I'm impressed with the quick response. I'm sorry to say I'm kind of glad im not the only one suffering for that damn code, and the power loss gives me hope although my power loss is constant, it never goes away. Even when im in neutral and I rev the engine it will do the exact same thing. If it went away I would just try to smog it one day when its doing good.
Its been a while since I played with fixing the problem but now I have a whole list of hope. I'm going to try and play with it this weekend. I'll start with the wiring since its the cheapest and I know it isn't the best, (there were some bad wires when I bought it, previous owner, was no electrician) how worth it would it be to invest in a wiring harness? thanks to everyone, the second I get a chance I'll update.

ec-williams

and does anyone know how to find out the proper voltage for the ecu terminals, i always figured if i hooked my tester up to it and reved the engine the voltage should cut out when the engine starts cutting out. there are so many wires and i don't know which are suppose to be hot, or what. the book i have isn't clear from what i remember,

MudHippy

Here's a copy of the 88-89 3VZE ECU pinout.


For more info here's the 1993 Factory Service Manual It's got the specifics for all the ECU wires(voltages)though the pinout isn't the same.

I've got some other things to fix first myself(namely an entire rebuild)just to keep 'er runnin' at all. But I've also been meaning to replace the cap & rotor(pretty coroded under there)and recheck the air gap on my distributor. So I'll try to take care of that soon too, so's I can check those off my list. Then the dreaded job of getting at the stupid VSS, that's stuffed up in the dash inside the combination meter. Man...I just hate tearing my dash apart! What a HASSLE! After reading that motor.com article though I'm pretty sure the VSS is gonna be the culprit. I've got all the symptoms. So when I can afford it I'm just gonna replace it and be done with that too. Everything else checks out A O.K. though on my vehicle.

Keep ya posted on any successful results, and maybe throw a pic or two up here when I get there.

ec-williams

yeah i read that article, and I don't think the vss is my problem, since mine happens all the time even when parked. Since my 4runner is a second vehicle I'm going to take the dash apart and follow every wire possible. Its a cheap hobby I figure, with any luck I'll find something...

ec-williams

ok, its been a while. I ripped the dash apart and started ripping out all aftermarket wiring. found out my 4runner once had an alarm. Unfortunately at some point the wires were cut and left laying together under the carpet. So they were grounding out. I cleaned up the wires and the engine light went off. However the timing is set to 7b and the idle is turned down as low as possible and its still at 1,100 RPMs. I can't seem to lower it with the Idle adjustment screw or TPS. Whenever I rev the truck to 1,700 RPMs and hold it, it will flutter to about 1,500 RPMs and return to 1,700. I'm getting there, need more help.