ECU swapped, coils swapped - STILL NO IGNITION ON 4

[ArtemLepilov]

Note - some people suggested that a faulty crank position sensor can cause that problem. Is that even plausible? please let me know - I really need to get the car running asap!!!

-Artem

[Rustam]

Note - some people suggested that a faulty crank position sensor can cause that problem. Is that even plausible? please let me know - I really need to get the car running asap!!!

-Artem

I don't find this plausible. If the crank position sensor was faulty you would not be able to start the car. And then - why necessarily 4th cylinder? There must be something else.

[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]

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]

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...

[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?

[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

[632 Regal]

go back and read Winfreds post.

[Jon K]

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