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Old 09-26-2019, 04:25 PM
ard ard is offline
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Quote:
Originally Posted by Hjaltivignis View Post
Hello all.

Got an X5 4.8i and when I start it cold, I get misfire on several cylinders 4,5 and 8, if I drive about 400-500meters turn ignition off and on again, than the problem is gone and the engine acts normally.

New spark plugs and injector in cyl. 8. Swapped the coils and the error does not follow the coil so the coils seem to be ok. Is there any known malfunction that you know that could be causing it?



Sounds like you have and issue with rich/lean... it can throw random misfire codes, but not linked to any one cylinder (the reason for this has to do wth how the DME detests misfires, CU calibrations, etc) The DME will declare a cylinder, but these are not NECESSARILY linked to one cylinder. (note: another give-away is a code of 'misfires- multiple cylinders'...this means the DME is seeing a lot of jiggle in the crankshaft accel and cannot decide which cylinder(s) to blame.)


Is this a cold start issue only?
Does disconnecting the MAF change this at all?
How old are your pre-cat O2 sensors?
What are your short and liong term fuel trims?
When you run a VANOS function test, results?

Last edited by ard; 09-26-2019 at 06:51 PM.
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