So I fixed the problem with my TII not haveing any spark. Now after doing research I found that the wires leaving the ecm to the injectors should have 12v with the key on. Mine is only showing .5v

anyone have an idea what it might be?

 

The light green/red, light green/white, light green/black and just light green wires in the small plug of the ECU are the wires that the ECU puts a ground on to make the injectors pulse.

If the key is ON, and the plug off, those wire in the plug, should show batt voltage. The voltage comes from the injector thru the other wire on the injector.

If your car is 1987 1/2 and EARLIER, the other wire gets batt voltage from the solenoid resistor package. The solenoid resistor package gets the power from the MAIN RELAY, and the power that passes thru the MAIN RELAY comes from the EGI INJ fuse in the engine bay.

The solenoid resistor is bolted to the fender directly below the AFM/air filter assy. Has a aluminium cover on it. Rectangular in shape.

If the car is newer than 1987 1/2, then there is no soleniod resistor package and the power to the injector is from the MAIN RELAY and the main relay is fed from the EGI INJ fuse.

IN either case, the power goes from the EGI INJ fuse........to the MAIN RELAY.........to a ORANGE in color plug in the passengers foot well................to the fuel injector (or to the solenoid resistor then to the fuel injector in the early car case).

JPG attached of the EARLY cars. 1987 1/2 thru 1988 cars are shown in the online manual.

 

thanks, i just checked the resistor per the haynes book and it is showing good. The previous owner of my car had rewired the main harness on the drivers side in the engine bay. I am starting to think he really effed things up.

 

I'm a little confused. Do you have a meter that you can check the light green wires in the small plug on the ECU???????? Key to ON should show batt voltage on each of the injector wires in the PLUG. That would prove the wiring b/t the Main Relay and the injectors is good without removing the intake manifold.

IN the jpg attached, not only the injector wires should have pwr, but the two wires on the far left should also have power. the B/W and the W/L (power the ECU).

 

ya I had taken a volt meter to them yesterday. Thats how I found I only have .5v at the plug comeing from the ecu instead of 12v.

 

you did check the fuses and the main relay?

 

ya main relay was pulled out of my rx7 that was running before i started to part it and the fueses are all good

 

So you don't have voltage at the ECU's small plug, is what I gather.

So it's like the diagrams in the book. The power comes from the MAIN RELAY then thru the ORANGE plug in the passengers foot well to the small plug on the ECU.

The power for the injectors goes thru the main relay ........to the ORANGE colored plug in the passengers foot well ...on to the resistor package .....then to the fuel injector. And then thru the fuel injector to the small plug on the ECU.

You need to see if the MAIN RELAY is pulling in. Pull it's two wire plug off. Key to ON. Then plug up the two wire plug on the MAIN RELAY. The relay should be felt to click or pull in if you will.

If it does not pull in, then pull the two wire plug off and see if there is batt power on one of the two wires in that plug with the key ON. The power comes from the ENGINE fuse if the key is put to ON or better.

The ground wire for that two wire plug for the MAIN RELAY comes from a ground block below the Trail coil assy.

The ENGINE fuse is good if your fuel pump runs with key ON and the fuel pump check connector jumpered and the fuel pump circuit has not been Mickey Moused to death.

The EGI fuses in the engine bay fuse box feed the power that passes thru the MAIN RELAY to the fuel injectors/coils/ECU.

I mean, the MAIN RELAY is or is not pulling in and the EGI fuses are good or not good.

But you say you have spark, so the ECU has to be getting power on the B/W and L/W wires. If that is so, then you just have to find out why the fuel injectors are not. You'd just pull the plug off the solenoid resistor package and see if there is batt voltage on the middle pin in the harness side of the plug. IF its not there, then it's be a problem with the ORANGE plug in the foot well BECAUSE that same fuse feeds the coils and you say you have coil power so the MAIN RELAY must be passing EGI INJ power thru it.

It's the black/yellow wires in the ORANGE colored plug that supply injector power b/t the FRONT harness to the EM harness.

Just in case..............the ECU does not send power to the injectors, so don't look at the jack of the ECU for an output to the injectors. The injector power comes from the injectors TO the ECU.