[retrorafin]

I recently bought a 2007 335i e92 from an old buddy. He didn't do the best to maintain the engine in this beauty and I've been cleaning up his mess.

Recently I changed the turbos, sparks and bov. Everything was doing decent Untill I go into WOT, I almost always catch a missfire on different cylinders each time (last time was 2,4 and 5) but the time before that was (1,3 and 5)

I asked my buddy if this had ever seen an intake clean and he said it hasn't, I'm currently at 148k and I know it should have been done at 80k…

Do y'all think the missfire is from clogged intake or possibly something else?

[Daaaaaaaan]

Probably needs a walnut blast.

While I'm not running a turbo, when I had an exhaust valve spring break, the reported misfires wouldn't be just that cylinder, but across other cylinders. An issue on one cylinder will cause issues on other cylinders on interference engines like ours. Probably some are worse than the others and not closing completely and issue exhibits at WOT, but will progressively get worse of course.

I suppose you could do a compression test to see which cylinder is the worst and the cause of the issue, but at 148k, probably due for a blast no matter what.

[BSM n54iS]

You're due for a blast 3x over at 150k holy shit

[retrorafin]

Originally Posted by Daaaaaaaan

Probably needs a walnut blast.

While I'm not running a turbo, when I had an exhaust valve spring break, the reported misfires wouldn't be just that cylinder, but across other cylinders. An issue on one cylinder will cause issues on other cylinders on interference engines like ours. Probably some are worse than the others and not closing completely and issue exhibits at WOT, but will progressively get worse of course.

I suppose you could do a compression test to see which cylinder is the worst and the cause of the issue, but at 148k, probably due for a blast no matter what.

Thanks man, Update! I cleaned them this weekend and still noticing a missfire at wot. Not nearly as bad now but still there.

Just charged the sparks and still there so I'm praying it's coils and not these crap injectors

[marvinstockman]

You need to monitor things like AFR and fuel pressure at WOT while driving.

You can monitor and record AFR with the $5 Torque App Pro software.

Remember, if you go lean at WOT, you will misfire, which means if AFR goes much higher than 14.7.

[marvinstockman]

Also, on a computer-controlled engine, you'll only get the amount of fuel that matches the airflow. A clogged air filter will really just reduce power.

[E93Dude]

At 148k I'd like to see a picture of what your intakes look like after you remove the intake manifold, and before cleaning. Mine were ugly when I did it at 100k. I bet you notice better gas mileage, if nothing else.

[retrorafin]

Originally Posted by marvinstockman

You need to monitor things like AFR and fuel pressure at WOT while driving.

You can monitor and record AFR with the $5 Torque App Pro software.

Remember, if you go lean at WOT, you will misfire, which means if AFR goes much higher than 14.7.

I can do a data log on Mhd and post it! I don't know much when it comes to reading the monitors but I have it on Mhd stage 1+ currently

[marvinstockman]

Do it and post it.