WFO

Just installed the 3.4 into my 91 4Runner. The motor came from a 2000 4runner. The donor truck ended up having the Theft Deterent system so I had to get a different ECM. I got one from a 2000 Tacoma M/T. Got all new connectors and wired them up over the weekend.

The truck will start but shuts off within a few seconds. I have spark even after it shuts off. I ran a jumper wire to the fuel pump to make sure that wasnt the problem. Im thinking its just starting off the cold start injector and then it shuts off. I have power to all my sensors and injectors.

Ive checked and re-checked my wiring and everything looks ok.

I am not running a rear Ox sensor. I have not wired up a resistor and capacitor yet. I read that these motors wont run with the Ox sensor unplugged. But I have it plugged in, just hanging under the truck. hopefully tommorow I will be able to wire that up.

It sounds like I am getting air in the intake after the MAF, like there is a leak, but Ive checked it and cant find any leaks.

What else should I be checking??

Also has anyone had problems with the ECM wiring being too short to mount the ECM in the original location? Mine are about 4" too short.

allnmstkn313

They'll run with out both o2 sensors, albeit poorly. I can say for sure that missing the rear o2, isn't your problem.

You've got spark, and fuel. I'd be thinking MAF or ETCS.

Yeah the wiring can be rather tight. After much fiddling, mine was just barely long enough.

WFO

ETCS - Electronic Throttle Controll System??? or do you mean Engine Coolant Temp. Sensor?

I was also thinking MAF, I never unplugged it while swapping the motor so it may have gotten damaged. Im going to test it later.

Im debating on building a box to enclose the ECM inside the engine bay and just extend the 8 or so wires that run into the body. My ECM literally hangs under my dash and ive done everyting I can to get them to reach.

mt_goat

X2, I drove mine 5 miles to the exhaust guy that way. It actually ran pretty good that way.

allnmstkn313

Electric Throttle.

Plenty of space under the Cig lighter area for an ECU, if you haven't considered it.

mt_goat

I'd unplug it until its actually in the exhaust stream, if I were you.

Have you tried turning the ECU upside down (plugs up)? You'll just have to redo the brackets when you do that.

mt_goat

I think you're on the right track, even ORS had wired my fuel pump wrong, but in my case it was running all the time the key was on.

WFO

I know the fuel injection system uses data from the Engine coolant temp. sensor, and I have 2 wires on the pass side front of the engine that were cut when I got the motor. Not 100% on the colors but im sure one of them is green. I assumed it was for the power steering sensor since it was in the same area. Now that I went back and looked at the EWDs the power steering only has one wire. If for some reason the engine coolant temp sensor was unplugged would the engine still run?


But I guess that might be the same as having the Ox sensors unplugged...

WFO

I dont think its related to the fuel pump. I think the ECM is not telling the injectors to pump fuel. I cant tell if im getting any pulse at the injectors. But I do have power there.

mt_goat

There should be a fairly easy way to test that. I know I have a wire tapped into one of the injector wires (hot one, not ground) that runs a water/meth injection system. It also has a little LED that flickers with every injector pulse. Maybe a little test light tapped in would test it.

Here's my old 2001 injector harness plugs, it looks like the black wire with the brown strip is the common (ground) wire so any of the other colored wires should be hot.

mt_goat

Here's my 5VZFE ECU in (note upside down) with one original bracket moved to a different set of holes:

allnmstkn313

Do you have a mechanics stethoscope? You should be able to hear the injectors 'clicking' even while cranking the engine.

jasond

What are you loosing, spark or fuel? Do you have a dlc connector wired up, if not get one in there and pull the codes and see what comes up. A 2000 4runner does not have a cold start injector. My guess is that it is not seeing the igf signal like it should, it seems like there was one guy here that had a pin back out of his igniter (i think?) or maybe it was the ecu, but either way the computer was not seeing the signal to let it keep running. Also remember that just because the harness plugged into the ecu doesn't mean that the pins are in the correct location. Be certain to check that the pin out is the same from the 2000 runner to the 2000 taco ecu and look closely at the igniter to ecu pins.

WFO

Did not realize there was no cold start injector.
I did not double check that all the pins were all the way in. With it being such a tight fit I could see where one may have came loose and is not in contact with the ECM.

Still no DLC. Apparently Toyota does not make these anymore, or at least thats what the dealer in town tells me.

I do have spark but I cannot hear the injectors ticking.

WFO

Got it running yesterday. The IGF wire was not connected to the ECM. Started it up and the idle was surging really bad. I had the MAF sensor in backwards. Turned it around and she ran good.

Thanks to all for your help.

mt_goat

Great Jason nailed it.

jasond

Glad to hear you got it going.