freezined

88 Toyota PU 22re, fuel injectors not firing.

Truck will start when I squirt starting fluid into intake, I do have fuel pressure at cold start injector. Last drove truck 6+ months ago, ran fine then. Stopped driving due to fuel leak, fabbed new fuel line from tank to engine.

Spark plugs are dry when turning over, but will light momentarily w/ starting fluid so my troubleshooting has been on the EFI/injectors.

11.7 volts at batt
11.6 volts at AM1 and AM2 fuses
Solenoid Resister at 11.7 volts, and 3.5 ohms
11.7 volts to injectors on blue and yellow wires, all cylinders
11.6 volt IGN fuse
10.5 volts EFI fuse
10.5 colts B+ to ECU terminals at EFI main relay
EFI Main relay within spec

At ECU
+B to E1 with key on, 2.3 volts
+B to ground 2.3v
+B1 to E1, 2.3
Batt to E1 - 11.5v
E1 to ground Zero volts
No 10 to E01 - 11.5
No 20 to E02 - 11.5
B+ to ground at diagnostic port under hood 2.3v

I'm no wiring master by any means, just dumb enough to try it. +B to E1 should be 10-14volts, but I'm not sure where to look from here.

I have a drop in v to 10.5 at fuse box, then 2.3 at ECU.

I have tried a different ECU with same results, truck has ran with this ECU in the past.

Injectors within spec and click when I hit them w/ 12v.

I've checked the ECU multiple times and it really is 2.3v, this has to be my prob, but I don't know what to check from here and it's making me emotionally unstable.

If you need more info please let me know, thanks in advance!

Terrys87

iTrader: (1)

88 is the odd ball year. You didnt by chance put different injectors from another year have you? I dont know if it is possible to change from another year injector to 88. You said you were getting voltage to the injectors so that leaves me wondering about the crimps in your harness. They sound like they are good, but on mine the harness would pass resistance checks but still not fire the injectors. On post #664 is what I went thru on mine. Link>>> https://www.yotatech.com/forums/f199...9/index27.html I may have some more info on my 86 Runner thread but tried to move to this thread.

You got fuel to the CSI so feel you have fuel to the injectors, chances of all of them being plugged is remote. You went indepth in your troubleshooting, so I wouldnt know what you may have missed. Great job on your troubleshooting.

TNRabbit

First, those voltages sound low. I'd remove & clean ALL THREE major grounds. What's your voltage at the battery?

Second, you might have clogged fuel rails. If your fuel line was rusted out, that's a distinct possibility. Get a mechanics stethoscope & check that the injectors are firing when it's turning over.

Third, exactly how did you fab a fuel line?

scope103

First off, 11.7 volts at the battery is pretty close to dead. It will mess up everything else, so pull it out, take it to a service station, and have them charge it over night. (It should be around 12.6, but temperature dependent.) While you're there, bring your meter and see that you're within 0.1v of their meter.

Based on your very careful diagnostics (you are a model for anyone else looking for a wiring problem) it sure looks like you've got a bad wire from the EFI relay to the ECM (my '94 schematic shows that as white-red, but the injector wires have a different color so it probably doesn't translate perfectly to '86.) DO check B+ to E1 (or to ground, E1 is ground but it looks like yours is okay) at the diagnostic connector; it's on the same side of the EFI relay as the ECM and should give the same (too low) voltage.

The injectors open when they are grounded by the ECM; they have 12v (or battery) voltage on them as soon as the key goes to "ON". So you've got 12v to the injectors, but they won't open because the ECM doesn't have enough power to switch the ground side.

Good luck, and keep us posted!

freezined

Thanks for the suggestions!

I bent a metal line to copy factory placement from 5/16 steel tube, and replaced fuel filter. Injectors are not clicking when turning over (that I can tell).

I'll charge the batt and get it up to spec. I agree on the bad wire - relay to ECM, I don't know if there's anything in between them to check. I don't think it's IGN switch, and I'll check the EFI relay again, otherwise I 'll run a wire from relay to ECM to check for a bad or short. I expect 12v or zero at ECM, but 2.3?? That's what makes me think it's a switch or relay or ???

Thanks again for the help, I'll keep you updated

Stu Pidasso

http://flic.kr/p/dvbqCj

This is a diagram of the wiring for the injectors. It even gives you the colors. I hope this helps you. I am trying to share it the normal way but I am brain dead this morning.

freezined

It's alive!

The 2.3 volts at +B on the ECU was the problem, but I was getting full voltage at the EFI relay, Even though the EFI relay passed the ohm readings I wasn't getting a good click when I turned the IGN key, so I took a $30.00 shot in the dark and replaced the relay and the damn thing lit right up. I now have 12.5 volts at +B on the ECU.

One owner, 281K and this is the first time it's let me down so I won't complain,...much.

For future searches if your voltage is low at +B on the ECU it could be the EFI relay even if the ohms are within range.

This is a great board, if I can't find an answer by searching there's penty here willing to offer help and encouragement.

Hadmatt54

A little more info when checking a relay. Your resistance readings were within spec, but all you were measuring was the resistance of the coil (electromagnet) that pulls the plunger in, closing the contacts. It's obvious that your coil circuit was intact, but your relay contacts (the side that carries the current) were shot. Next time you really want to test a n/o (normally/open) relay:- test the resistance of the coil side like you did, then pull out the relay and connect the coil side across a 12v. battery. That will energize the coil and close the contacts, then take your meter and measure the resistance of the closed contacts, it should be zero ohms or very close to zero. If you get a high resistance reading that means the contacts are burned and pitted not making a good electrical connection or if you get an "OL" (overload) reading on a digital meter that means the contacts are burned so bad that they are melted away and not making any connection at all. The overload connection on a digital meter is the same as an infinity reading on an analog meter.

freezined

Good info Hadmatt, makes perfect logic. I couldn't find anything else in the FSM for testing the relay other than ohms but suspected it was the problem when I had low resistance from the relay ECM terminal to the ECM +B to rule out any shorts.