ECU swapped, coils swapped - STILL NO IGNITION ON 4

[ArtemLepilov]

Thats what Im thinking - my problem seems to be really weird. Just checked the wiring harness thoroughly - it is in good shape, continuity test shows all good. ECU is brand new from a different car, which worked in it fine, and my ECU didnt seem to be bad anyway.

I got no idea what it can be - everything is fine and is there, it just isnt producing any spark on cylinder 4... People suggested crankshaft pos sensor and camshaft position sensor. Can that possibly cause it - i head if the voltage is different on the signal form the CPS it may misfire on that particular cylinder whenever the voltage is different at that particular time - its a longshot... but i have to test EVERYTHING POSSIBLE... Does anyone know for sure?? I am seriously lost at this point...

-Artem

[Rustam]

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

Have you actually seen no spark produced in the spark plug connected to the coil but out of the engine during cranking?

[Rustam]

Thats what Im thinking - my problem seems to be really weird. Just checked the wiring harness thoroughly - it is in good shape, continuity test shows all good. ECU is brand new from a different car, which worked in it fine, and my ECU didnt seem to be bad anyway.

I got no idea what it can be - everything is fine and is there, it just isnt producing any spark on cylinder 4... People suggested crankshaft pos sensor and camshaft position sensor. Can that possibly cause it - i head if the voltage is different on the signal form the CPS it may misfire on that particular cylinder whenever the voltage is different at that particular time - its a longshot... but i have to test EVERYTHING POSSIBLE... Does anyone know for sure?? I am seriously lost at this point...

-Artem

take a look at the camshaft position sensor. does it look like it can provide variable signal at any point during its turning or only within a limit if few degrees? if it does not sense all along the circumference then it cannot provide cylinder specific information.

[ArtemLepilov]

Have you actually seen no spark produced in the spark plug connected to the coil but out of the engine during cranking?

Yes - i tested every coil separately at ignition mode, every other coil fired the spark plug - on the same spark plug that i tested other coils on, except #4, swapped the coils around to make sure they worked, the same coil that didnt fire on #4 fired on a different connector. I grounded them on the engine case, and it produced a spark on others.

-Artem

[ArtemLepilov]

take a look at the camshaft position sensor. does it look like it can provide variable signal at any point during its turning or only within a limit if few degrees? if it does not sense all along the circumference then it cannot provide cylinder specific information.

I somehow doubt that the sensor provides a clinder specific information. I will double check tomorrow though..

-Artem

[Rustam]

I somehow doubt that the sensor provides a clinder specific information. I will double check tomorrow though..

-Artem

I doubt that too. The wheel that stimulates the sensor has a small extension that covers no more than 15 degrees. And the sensor itself is not radial:

http://img.autopartswarehouse.com/li...1027370BOS.JPG

So this tells that the system is unable to provide camshaft position with respect to a cylinder.
_____

If you checked the coils in that fashion and another ECU did not provide a change then the only culprit is the wiring...

[632 Regal]

go back and read Winfreds post.

[Jon K]

Like I said last night in IMs - test the fuel injectors.

[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