[Ander335xi]

Hi guys!

I have a problem with my e91 335xi N54. When I start the engine in the morning with the cold car, it starts perfectly and hard but when the idle speed goes down to 600 rpm, the engine starts to shake and make noises, it smells a lot of gasoline and moves the needle of the revolutions dances a little. when the idle goes down to 700 or so, the engine sneaks out and stays running with four cylinders and sometimes with 3.

Cylinders 1 and 2 always fail and sometimes 3 also. I took the injector 1 and 2 and the coils and changed them to the 5 and the 6 to see if the fault moved from site and find out what it was, but whatever the fault always jumps in the cylinders 1 and 2 and sometimes the 3 too. I think that if it were the O2 sensor, the 3 cylinders would always fail and not only sometimes. the spark plugs are less than 10000km, the VANOS valves are new. I do not understand why it always fails in the same cylinders.

Do you have any idea what it could be? the faults are these:
-29cd misfire cylinder 1
-29ce misfire cylinder 2
-29cc multiple cylinder misfire.

I would appreciate very much if you would give me some guidance

[Ander335xi]

This only happens when I start the first time cold. if I turn off the engine and restart the car it works perfectly

[relative4]

Smoke test. What are your fuel trims?

[buddyboy]

Originally Posted by relative4

Smoke test. What are your fuel trims?

Im new to these BMW's, whats the thing to check for fuel trims with MHD?

[MysticRob]

Originally Posted by Ander335xi

Hi guys!

I have a problem with my e91 335xi N54. When I start the engine in the morning with the cold car, it starts perfectly and hard but when the idle speed goes down to 600 rpm, the engine starts to shake and make noises, it smells a lot of gasoline and moves the needle of the revolutions dances a little. when the idle goes down to 700 or so, the engine sneaks out and stays running with four cylinders and sometimes with 3.

Cylinders 1 and 2 always fail and sometimes 3 also. I took the injector 1 and 2 and the coils and changed them to the 5 and the 6 to see if the fault moved from site and find out what it was, but whatever the fault always jumps in the cylinders 1 and 2 and sometimes the 3 too. I think that if it were the O2 sensor, the 3 cylinders would always fail and not only sometimes. the spark plugs are less than 10000km, the VANOS valves are new. I do not understand why it always fails in the same cylinders.

Do you have any idea what it could be? the faults are these:
-29cd misfire cylinder 1
-29ce misfire cylinder 2
-29cc multiple cylinder misfire.

I would appreciate very much if you would give me some guidance

Did you recode the injectors into the DME after making all those changes?

[Ander335xi]

Originally Posted by relative4

Smoke test. What are your fuel trims?

I can not know now, just today I left the car in the workshop.

[Ander335xi]

Originally Posted by MysticRob

Did you recode the injectors into the DME after making all those changes?

Yes i did, i recode all the inyectors

[Ander335xi]

Does someone else know something?

[Ander335xi]

the compressions are fine and the new spark plugs were put on. We do not know what else to look, any subject?

[type-dRew]

Originally Posted by Ander335xi

the compressions are fine and the new spark plugs were put on. We do not know what else to look, any subject?

If they don't know where else to look, i'd start looking for a new shop immediately.

Datalog your car if you want help on the internet, otherwise we are just guessing, it could be several things. Seeing that its isolated to one bank, fuel injectors, o2 sensor, coils, etc all make sense

[relative4]

Originally Posted by type-dRew

If they don't know where else to look, i'd start looking for a new shop immediately.

Datalog your car if you want help on the internet, otherwise we are just guessing

All this plus smoke test.