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HyTeK HyTeK is offline
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Posts: 20
Join Date: Mar 2015
Car: 2009 335xi E90
Default 11-23-2018, 11:46 AM

I had the same issue where I had Oil in Cyl6, and enough to seep through the threads into Cyl6. This alone wasn't causing my issues though. The Oil leaking was from a valve gasket going bad.

I started to have misfires in Cyl3 even on stock maps. I already swapped out all plugs with new. All new coils were installed about a year ago from bavauto. I was now down to either the injector or the LPFP (HPFP was also replaced a few years ago). I was having very long cold starts, and the last morning where it completely died and didn't start was the first night it froze in my area. That particular morning the entire car was shaking and shuddering, I was throwing a ton of white smoke out the back and tons of unburnt fuel coming out the exhaust, and misfires in ALL cylinders.

I started to compare all the injectors values to what was in the ECU. After closer inspection I noticed that injector 3 was not the same as all the others. I bought the car used with 21k miles, and someone before me already had one injector replaced. But the bad thing was the injector 3 values did not match what was in the ECU!!! They were off considerably. The index for all the injectors were in the same class with 7 or 9 (class being index version 1-9, or 10+), but the injector values were not even close.

Funny enough I had a spare injector that matched the index, but I only had one. Yes, you are suppose to replace them in groups of three, front bank or back bank, but I was desperate. Luckily the fuel rail is individual per injector. I swapped injector 3, waited for it to warm up a bit, started the car, and to my surprise it started and ran for 5-10 minutes with not a single hiccup! On closer inspection the old injector 3 was stuck open, and just dumping fuel into cyl3.

However, the next morning everything died again. Misfires in every cyl. Come to find out, my LPFP was dying a horrible death. Got that replaced last week, and the car is back to running 400-450bhp, and feels as good as when I first got the jb4 on it. Also checked to ensure the original white smoke wasn't a leak of coolant or other issues. Everything checked out, and car is running clean and strong again.

Did the wrong injector values potentially cause the premature death of injector 3? Or the premature death of the LPFP? Who knows. But I double checked EVERY injector and they are all accurate now.

Sorry for the long story, but just wanted to explain the process of what happened to me.
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