Rustycan

Hi i recently bought a 1988 toyota 4x4 and i was driving it around off road, and i jumped a hill with it, and when i hit the ground it died.the lights stay on and such, but it cranks and cranks and cranks but never will fire over. I started with the basics and went through the ignition system replacing everything i could coil sparks hard, new distributor, rotor, rotor cap and plugs. The plugs spark is orange, which i dont understand. Its got a good battery in it, and such. I got tired of messing with it and took it to a shop and they kept it for 3 days only to tell me they cant figure it out, and said it has no injector pulse, i asked him if fuel was even making it to the injectors. He said no fuel, is moving. Also when i got the truck home after the jump i noticed the main ground had come off. Could that of fried something? where should i start i dont have the tools to electrically test really, i dont know if i should try a computer and go from there or what, i am at a loss right now.

RUNUMHARD

I think the computer would be a good place to start, i had an experience with a truck dying out on me, no injector pulse. replaced the ecu and it was all good.

Aussie22r

Try the injector resistor, it plugs into the main relay and without it no squirt.
A quick way to test is disconnect the loom from the ecu. turn the key, test for voltage FROM the injector pin. If yes short this pin to ground while you have a mate listen for the click.

This will prove the injectors work and the wiring is fine.

Use the attachment for the pinout. Its from the perspective of looking at the ecu terminals (if that makes sense)

Rustycan

Ok i will try that when i get home, if it turns out to not be an ECU problem where should i go from there?

Aussie22r

Start unplugging things, checking terminals and resistance values. Look in fsm's for these values. Test the injectors by connecting a 9v battery to the terminals listening for a click.
Open up the ecu and look for any obvious signs of failure.

Good luck with it.

Rustycan

What year ECU will work in a 1988 4x4? if i cant find a 84 to 88 ECU

Jkludy

We are lost on our 86 4runner 22ret.. I have replaced timing chain, cap and rotor, radiator, circuit opening relay, main relay and it starts but won't stay running. When we bought it after Christmas it started and test drove rough but knew it wouldn't be a problem to tune up. drove it up on car trailer and off at our home and parked in garage. Did the above work and then now it won't stay running. It will run when I use starting fluid. I think it is fuel related but not sure where to go and test. We lost our injector pulse. I get a little in the beginning and then it goes away. I have checked all the grounds and looks for air leaks. Help would be much appreciated.

Co_94_PU

iTrader: (-1)

Good day, and welcome to yotatech!

You can and should start your own thread for debugging purposes. It makes it easier on people searching for similar problems. And gives a clear list of diagnostics already performed...

Test for power supply to the injector resistor, silver box on the right-hand inner fender with the fins.

check the injector resistor resistance.

probe an injector plug for power.

​​​​​​The opposite pin for continuity to the ECU.

Injector coil resistance

Resistance between the ECU and the ECU ground, located at the junction of the upper(plenum) and lower intake manifolds.

If all that checks OK it is most likely the injector driver circuit in the ECU.