Recent coil/misfire problems

[Muleears]

Originally Posted by 270_BMW

If it is exclusively on 4,5,6 I would check your grounds for that bank. I had an issue with 1,2,3 a couple months ago. Turned out to be a seeping Valve Cover Gasket, was getting oil everywhere and down in the wells, but also shorted out my ground.

I looked at the grounds, they are firm and dry, the wells are dry also. IIRC the misfires I have been in 2,3,4 and/or 3,4,5. It seems to always include #3 and never 1 or 6 though.

Thanks for the help guys, this is all good stuff.

[upallnight]

Originally Posted by Muleears

Would this be enough of a misfire to trip the SES light and make the DME shut that cylinder off? If it doesn't smooth out on its own and trips the SES, I have to clear the codes for the misfire(s) and it then runs smoothly.

Once the SES light is tripped, the DME shut off fuel to the cylinder that is misfiring. If the flooded cylinder can clear itself before the SES light is tripped the DME will not shut down the injector.

An injector that is shut down by the DME due to misfire can be reset by just turning off the engine and restarting the engine. The misfire counter will reset itself when the engine is turned off. You do not need to clear the code.

[Muleears]

Originally Posted by upallnight

Once the SES light is tripped, the DME shut off fuel to the cylinder that is misfiring. If the flooded cylinder can clear itself before the SES light is tripped the DME will not shut down the injector.

An injector that is shut down by the DME due to misfire can be reset by just turning off the engine and restarting the engine. The misfire counter will reset itself when the engine is turned off. You do not need to clear the code.

That is good to know and much less cumbersome than pulling out the code reader. I'll give it a try in about an hour when I leave for work. But if the SES is tripped the injector will stay off until the code is cleared? A restart won't help?

Thank you for the enlightenment.

[Muleears]

Start this morning (at 46*) was better than most. Started with a mild misfire but smoothed out in about 15 sec. and no SES or need for a restart. I'm encouraged. I'll try a bottle of techron and hope that cleans up a leaky injector (or three) and see how it goes from there. We have warmer weather through friday, but colder weather returns for the weekend and next week.

[upallnight]

How much mileage is on your X? If you haven't been using an additive to clean the fuel system on a regular base, I would look for a shop that can perform professional fuel injectors cleaning service.

https://www.youtube.com/watch?v=9UKEON2wIkA

[andrewwynn]

i actually like that idea. i think i could use the same on both our cars.

[upallnight]

Or if you're a DIYer and don't mind spending money on tools, you can get this:

https://www.ebay.com/itm/Auto-C-100-....c100677.m4598

[andrewwynn]

That's cheap I guess I know what my Valentine's gift is going to be


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[Muleears]

Originally Posted by upallnight

How much mileage is on your X? If you haven't been using an additive to clean the fuel system on a regular base, I would look for a shop that can perform professional fuel injectors cleaning service.

https://www.youtube.com/watch?v=9UKEON2wIkA

The X has 294,5XX miles. I just got it in November. I don't know a lot about the history and even less about the fuel system. I like the idea of cleaning and testing the injectors though.

[upallnight]

Originally Posted by Muleears

The X has 294,5XX miles. I just got it in November. I don't know a lot about the history and even less about the fuel system. I like the idea of cleaning and testing the injectors though.

With that kind of mileage on a 14-year-old X that equates to roughly 21,000 miles per years. She been driven hard and put away wet. The 50,000 miles warranty only lasted 2.5 years.