cyl #3 coil is not getting a pulse. -UPDATE FIXED-

[kmm111]

Originally Posted by Elkman

I may have been wrong, both scanners are for only BMW autos one I got from Bavarian autosport 10 years ago it is round with a 2 digit display and 2 buttons. the other one is new and has more capabilities like live data. I thought you were talking about the ones the dealers used.

Well sort of. Something that emulates the factory level tool. Cheapest option IMO would be PA soft with a PC link cable or possibly INPA. What kind of codes are you seeing? If your seeing a code like p0303 that most likely is not specific to BMW. But a 2744 hexadecimal code would be. What’s interesting to me is that your DME is not generating a coil fault code, nor the fuel injector shut down code.

[upallnight]

Originally Posted by Elkman

What happens is when I clear the misfire code and start the car #3 injector works for 15 or 30 seconds then the DME turns it off which is normal when it detects a misfire, I think. This happens the same time the check engine light comes back on.

A misfire on a modern engine does not mean that the spark plug or coil is the problem. A misfire in a modern engine means that the cylinder is not producing as much power on the power stroke as the other cylinders in the engine. This could be due to lower compression number in the cylinder or a slightly clogged injector that doesn't spray as much fuel into the cylinder.

Is the compression number in the offending cylinder the same as the other, at least within 10%? Have you checked the spray pattern of the injector in the misfiring cylinder the volume of gas it is spraying within a given time?

[Elkman]

Originally Posted by Elkman

I used a grounded plug tester light as well as moving coils and plugs around, all coils were good. I tested the pulse to all the fuel injectors as well as the operation of all fuel injectors all were good. I did a smoke test to check for vacuum leaks. all was good. I check cylinder compression and fuel pressure. all were OK. I have concluded cyl #3 coil is not getting a pulse.

I need to check for continuity to eliminate the harness as suggested, I need to find out the best way to do that?

Thanks for the help Guys.

Cylinder compression was within 10%. of each other.

I have concluded cyl #3 coil is not getting a pulse. See above.


Bad wire harness? Bad DME?

I just bought a used wire harness on E-Bay to use as a test tool since I am weak when it comes to electronics.
Thanks

[80stech]

It might have been better to buy a used DME instead of a harness.

[Elkman]

Originally Posted by 80stech

It might have been better to buy a used DME instead of a harness.

I thought of that, but I decided to try the harness first.
Would it not be better to send my DME off to have it repaired? I have found a couple of places that say they can fix/rebuild them without the security VIN problems I have read about.

[upallnight]

Originally Posted by Elkman

I thought of that, but I decided to try the harness first.
Would it not be better to send my DME off to have it repaired? I have found a couple of places that say they can fix/rebuild them without the security VIN problems I have read about.

If the DME is original to the car, why should there be a security problem after the repair? The DME is married with the EWS module so if the original DME is repaired it should still be married to the EWS module.

I can see a security problem if you sent them a non-original DME to have it repaired and install in your car.

[Elkman]

Originally Posted by upallnight

If the DME is original to the car, why should there be a security problem after the repair? The DME is married with the EWS module so if the original DME is repaired it should still be married to the EWS module.

I can see a security problem if you sent them a non-original DME to have it repaired and install in your car.

Exactly, that is what I tried to express as the reason for repair instead of buying a used one.

[wpoll]

I think that *some* repairs might wipe the data on the DME/DDE. Like replacing an EEPROM...

Then even your "original" DME/DDE will need re-coding.

But I image that type of repair would be VERY rare.

[Astrok]

What was it?

[AussieXer]

I would also be interested to know.