Motomeister

Got cylinders 1+3 not firing on my 22re. Tested the resistance on the injectors all four check out at 3.0ohms. Figured i would check resistance on the wiring going from the injector which i assume goes back to the ecu. Im getting 7.5 ohms of resistance back to the ecu but only 4ohms on the cylinders that are working.

Spark plugs are sparking, injectors 1+3 are not operating, used screwdriver as stethoscope and no ticking from injector.

Is it safe to assume that my wiring is fried from shorting the battery positive terminal to the intake manifold?

Are there pins to test these wires on the ecu, like from ecu-ground?

Any help would be greatly appreciated.
I wish i woulda followed the manual and actually disconnected the battery before messing with the throttle body, lol i guess that was my fault.
Thanks,
Jake

4Crawler

iTrader: (3)

Check the injector wire splices, should be about 6" up inside the wire loom:

Motomeister

thats some great info and diagrams right there, gotta look at it a little more. Thanks a bunch, ill post back up with some results.

Motomeister

so i tested my wires from injector to splice and they all checked out.
tested wires from resister on firewall too splice and the powere wires checked out. just gotta check the ecu to injector wire. if that checks out where am i at??

4Crawler

iTrader: (3)

Not much to that circuit, you get power to the injectors via the big resistor. Then the ECU grounds the injectors to make them turn on. And all injectors "see" the same power feed and essentially they all "see" the same ground and are supposed to all fire at the same time. So figure out why some turn on and some don't by comparing all the similar points.

Motomeister

that why the ecu to injector wires are kinda all spliced in one group? those are just ground.

if there is one bad connector on the injector does that mean its pair wont fire? it shouldnt considering they each have their own ground? i guess i should assemble the thottle body back up and start it and see what types of volatages im seeing coming to the injector? there any referances for taht sort of thing?

4Crawler

iTrader: (3)

Yes, you need power and ground to make the current flow through any injector and make it turn on and let fuel flow through it. Essentially all the injectors are in parallel with each other so if one is bad, the other 3 still work. But some of the splices and connectors are in places that feed 2 or 4 injectors, so a problem there would affect 2 or 4 injectors.

As far as testing, you should see 12 volts or so at all the injectors and then momentary pulses of the ground wires.

Motomeister

whats the deal with the resistor inbetween the power and injector? what purpose does taht serve? protects it from frying the solenoids?

4Crawler

iTrader: (3)

Resistor is there to limit the current flowing through the injector coils (solenoids) and the ECU. Since the injectors are in the 3 ohm range, if you had no ballast resistor, you would see 12/3 or 4 amps flowing though each injector coil (12 volts / 3 ohms = 4 amps). Probably would fry the coils in short order. So the ballast resistor adds resistance to that circuit to keep the current down to some nominal value.

Motomeister

alright, thats what i was thinking. i have checked all my wiring and it all checks out with resistance checks. im getting volatage to my injectors and have tested a diferent known good ecu wish no help at all.

would there be a way for the resistance to check out on the injector but the solenoid not be working?

4Crawler

iTrader: (3)

Well, you need a complete circuit and it needs to flow enough current to make the injectors turn on and off. The ECU grounds them, but to do so it makes an internal connection (via No10 and No20 pins). And the ECU needs a good connection to ground, via a sheet metal screw and then that sheet metal needs to be attached somehow back to the battery "-" terminal to make up that ground. So lots of places where you could run into problems.

But I think it was mentioned that 2 injectors were working and 2 were not. If that is still the case, try to find out what is different between the 2 working and non-working circuits.

Motomeister

ive got continuity from injector wire back to terminal 10 and 20 on the harness. that means i got a short somewhere in the harness...

Motomeister

So i started my truck today to check a few voltages on different wires and what not. Fired up and runs like a top no problems at all. Kinda weird. Problem solved and have no idea what i did to solve it.

BenLEXus

F. F dude. I stumbled upon this thread when i hit a brick wall with my 87' 22re 4runner. I've got the same problem you did only my 2 and 4 cylinders got no juice! I've found other threads with similar problems, but you have basically the same exact problem.
I kept reading thinking it was gonna show me the light. But nooo.
Just kidding though. I gotta give big props to 4crawler for the diagram. I never thought to cut back the shrink wrap and check the splices. Hell, i didn't even really think they were spliced together in there. Friggin' awesome. Hopefully i can just cut it out, check everything and fire it up like Motomeister. Congrats on getting it firing on all 4. Had to register here just to give some props to both of you.

Motomeister

Good luck to you man. I had that damn think assembled and reassembled like 3 times and the last time went to put it back together and was gonna check voltages and there was no reason to, so i went ahead and did it anyways. I would definitely check those splices out though, they are not what i would have expected from a stock harness. And yes his diagrams helped a ton.

BenLEXus

Holy crap! Got my harness uncovered and after cleaning a lot of moisture from the wires i found it. I have a broken splice. Its broke clean from the splice and its the blue wire from the solenoid. Thats gotta be it since i dont have 2 and 4 and blue controls those two injectors. Wow. i can't wait to get it all reassembled tomorrow and fire it up. Thanks guys! I'll keep you posted. Hey Motomeister, Did you have a lot of moisture and the smell of mold when you took all the tape and plastic off your wiring?

Motomeister

well the reason all this happened was because of a coolant leak right next to the throttle body, so i beleive it got wet and caused this to happen, once it dried back out it was all good. My splices were all connected but not by too much. All i smelled was coolant.

BenLEXus

Quick question. I got the wiring back together and cut apart some other splices and used butt(i think thats what they are called)connectors to test it all before i do a permanent splice. What is the best option for splicing the wires back together. I doubt the connectors i used are a great option as they are just crimped. Have a soldering iron and i was wondering how other people have gone about resplicing the factory connections. Thanks for your help.

abecedarian

solder and shrink wrap

ozziesironmanoffroad

x2 on solder and shrink... that is one deadly combo that will not be going anywhere anytime soon.
*edit* and i just realized this thread is old.... damn.