Wile E. Toyote

I have an 88 22re that is the frankenproject result of a cab swab/efi swap.

Anyway, it starts and runs for a few seconds then dies. I don't think the injectors are firing. It only seems to run off the cold start injector fuel.

How can I test the injectors being pulsed? I know they are good, I've had them rebuilt and saw all 4 firing like champs. All the injector connectors have 12v. I know that they fire to ground, but I'm not so smart and don't know how to manually force them to fire. Also, what would prevent them from firing. ECU? TPS? Fuse? Relay?

Also, I am getting a code 51 along with this problem, not sure if it would be related or not.

Any assistance would be much appreciated. Thanks.

tampabayota

use a noid light

mt_goat

Search 4crawler's posts, he answered that question recently but I can't remember the answer now.

This may have been the one I was thinking of:
https://www.yotatech.com/forums/f120...-issue-161965/

annoyingrob

I just use a lightbulb. Go to the store, and pick up those little 12v push-in light bulbs, and beld the contacts down. Then, insert the contacts into the injector plug.

Wile E. Toyote

That is an excellent idea. Thank you.

Wile E. Toyote

Ok, my injectors are simply not pulsing.

I'm down to the pickup coil in the distributor, or the ECM. What else could be causing it? Also, how would I test the ECM to see if it is sending the signal?

annoyingrob

Get a pinout, and hook a multimeter up to the injector pins. They're called 10 and 20 or something like that.

It's posible your injector resistor pack is dead, or not getting power.

Wile E. Toyote

Ok, another question. The injectors plugs have 12v, on both sides. Is this right?

annoyingrob

Sort of. One side is always connected to 12V, the other side sits at 12V when the ECU has the injectors off, and drops to ground then the ECU wants to fire the injector.

The fact that the ECU is holding the line at 12v tells you that it IS hooked up properly, the ECU is likely not getting an RPM signal.

muddpigg

iTrader: (1)

Bet you forgot the ground that comes out of the same wiring harness as the injectors, it attaches to the intake manifold. Goes rear two on the enter side of the mating of the upper and lower halve of manifold think it goes same area as the brace that runs to the block (but don't quote me on that brace thing). It easily hides and is over looked. Guess how I know.

tampabayota

yep check for ground

Wile E. Toyote

Yeah, I've checked that. This is the bundle of wires (3 I believe) that comes out of the harness and grounds to the plenum?

Wile E. Toyote

This still doesn't make any sense to me. Why would both sides of the plug need to be at 12v when not connected? Shouldn't one side just be dead and then drop to ground while the other sits at 12v, therefore completing a circuit.

I also came across this
http://www.4x4wire.com/forums/showfl...=&fpart=1&vc=1

annoyingrob

It's a lot easier, and safer to build a semiconductor device to switch between 12v, and ground than between an open connection and ground.

Wile E. Toyote

Thanks rob, it still doesn't make sense to me but not everything does. I just wanted to be sure that I didn't have a short somewhere causing my problem. Although I think I may have a wiring problem with the grounds.

Wile E. Toyote

Woohoo, she runs!!!!

Huge thanks for everyone's help and suggestions. And a special word of thanks to 4Crawler for all his knowledge and information on this site and his own, he is a toyota god.

Turns out that I had a broken wire in my harness, one of the 3 wires from the ignitor through the plenum and to the ECU. It carries the signal to the ECU to pulse the injectors. It had just broken inside the harness (little 18 guage POS). Had to pull the intake (again) to get to it, I have that process down to about 10min now. Soldered it up, shrink wrapped and Eureka.

Again, thanks to all.

annoyingrob

Told you the ECU wasn't getting an RPM signal


Glad you got it working.

muddpigg

iTrader: (1)

Glad to hear.

Wile E. Toyote

Yeah you did, but that was the easy part. The PITA was finding out why, I checked every component in the circuit and they all spec'd out fine. I think I danced a jig when I finally found the broken wire. Why in the hell they used spindly little 18 guage wire for such a critical component I'll never understand.

but thanks again rob

mt_goat

Have you seen the fuel pump wiring? I think its even smaller than 18 gauge.