ECU swapped, coils swapped - STILL NO IGNITION ON 4

[ArtemLepilov]

Today i pulled everything off the engine - namely the harness will try to find a cause for the misfire problem. This really pisses me off... Does anyone know what else I can do?

-Artem

[granit_silber]

Today i pulled everything off the engine - namely the harness will try to find a cause for the misfire problem. This really pisses me off... Does anyone know what else I can do?

-Artem

Could the spark wire be bad?
-ashley

[ArtemLepilov]

Possibly - thats why I took the wiring harness off - im going to check and see... Unfortunately I need to do a hell of a lot of work in astronautics at the same time and ship a lot of items... This is a very very bad time for me... This week is going to be hell.

-Artem

[mholbrook]

Did you try moving coil from number 4 to another cyl to see if you just have a bad coil?

[winfred]

did you check that you were getting the signal to that fuel injector?, the power should be constant with the key on and the computer triggers it with a pulsed ground signal

[ArtemLepilov]

Are both the coil and the fuel injector work together with the same pulse at the same time?

-Artem

[winfred]

no but one can shut down the other

Are both the coil and the fuel injector work together with the same pulse at the same time?

-Artem

[ArtemLepilov]

so, when there is no continued circuit on the fuel injector, there is no spark? Is that how it works?

-Artem

[Bill R.]

things that may or may not help... first off the dme won't shut off the spark to an individual cylinder if there's no continued circuit on the fuel injector.

It has a feature in the DME known as the catalytic converter protection on your car which is dme version 3.1.
This feature will shut off the injector to any cylinder that a fault is detected in the coil primary circuit. The later cars which have 3.3 and higher monitor the primary and secondary ignition circuit and shut down the fuel injector if needed,but yours only monitors the primary. This is to keep from dumping raw fuel into the cat.
If you have a injector fault it won't shut down the coil since spark without fuel won't cause a cat to overheat

Next since you have changed the dme and the coils both, have you checked for voltage at terminal 3 of the coil connector with the key on?

All of the coils have 12v at them when the key is on and the dme makes and breaks the ground to trigger the spark. If you look at the harness you'll see that all of the coils have a junction point in the harness where they all meet for the positive supply line. If you don't have 12v at terminal 3 with the key on then back trace it and find out at what point you do.

so, when there is no continued circuit on the fuel injector, there is no spark? Is that how it works?

-Artem

[ArtemLepilov]

things that may or may not help... first off the dme won't shut off the spark to an individual cylinder if there's no continued circuit on the fuel injector.

It has a feature in the DME known as the catalytic converter protection on your car which is dme version 3.1.
This feature will shut off the injector to any cylinder that a fault is detected in the coil primary circuit. The later cars which have 3.3 and higher monitor the primary and secondary ignition circuit and shut down the fuel injector if needed,but yours only monitors the primary. This is to keep from dumping raw fuel into the cat.
If you have a injector fault it won't shut down the coil since spark without fuel won't cause a cat to overheat

Next since you have changed the dme and the coils both, have you checked for voltage at terminal 3 of the coil connector with the key on?

All of the coils have 12v at them when the key is on and the dme makes and breaks the ground to trigger the spark. If you look at the harness you'll see that all of the coils have a junction point in the harness where they all meet for the positive supply line. If you don't have 12v at terminal 3 with the key on then back trace it and find out at what point you do.

Hi Bill. I checked all the coils a while ago, as well as checking for continuity - all of the coils were getting power 12V - 13.46 to be exact. The Coils, the DME wiring is fine and the DME is fine. I can test fuel injectors while the DME is on the car.

Meantime Im putting the harness back on the car.

-Artem