Miss firing on all cylinders, only one hot and idling

[Bigjaybird]

OK I have a BMW M3 2008. The car runs perfect when it’s cold after the car heats up only at idle RPMs jump in the car goes into restricted mode computer shows through diagnostic scan that is shutting off injectors intermittently changed coils changed plugs has X pipe and cat delete, and tune. No other codes are being thrown besides misfire on 12345678. Any help would be greatly appreciated.

[Redd]

Remove the intake and plenum and drive the car. If the misfires go away you probably have an intake air leak somewhere.

[Bigjaybird]

It was smoke tested and no leaks… it only give’s misfire on all cylinders no other codes…

[RocketyMan]

Welcome to the forum. What EXACT coils and plugs did you put in? This is VERY important....

[Redd]

Originally Posted by Bigjaybird

It was smoke tested and no leaks… it only give’s misfire on all cylinders no other codes…

I had same issue in past, misfire all cylinders. Smoke/water tested the plenum and intake 3x and no leaks. Turns out the IAT sensor bung was leaking but only under vacuum.

I ran the car without plenum and sure enough, no more misfiring. That convinced me it was something in the plenum. After a detailed inspection we found 3 small internal tabs in the IAT bung had been damaged. Putting some black tack around the IAT sensor fixed the problem.

[Bigjaybird]

@Rocketyman I got the Duralast coils with the BMW logo on them and NGK spark plugs $17 ones… I re-gapped the spark plugs but now I’m getting codes on all four cylinders for the coil packs

[Bigjaybird]

The misfire is now gone, but the car is still shutting itself off and installing out only codes are on all state cylinders for the coil packs, which I just replaced look at picture above

[spammysammich]

https://www.bimmerpost.com/forums/sh...php?p=29002028

Unfortunately the only coils that seem to still work with our cars are the BMW oe coils or eldor.

[Bigjaybird]

These are the coils and plugs I got…

[Ervin87]

Throw those coils away. Junk. No wonder you are having misfires. There was a time where alternative options worked, but not anymore. You have to buy OEM coils. You don’t have to replace them all, just the bad ones.

You need NGK Spark Plugs - LKR8AP (don’t touch them, just install them).

[Bigjaybird]

Originally Posted by Ervin87

Throw those coils away. Junk. No wonder you are having misfires. There was a time where alternative options worked, but not anymore. You have to buy OEM coils. You don’t have to replace them all, just the bad ones.

You need NGK Spark Plugs - LKR8AP (don’t touch them, just install them).

Where can I get the coil packs at the best price…

[spammysammich]

You’re going to pay at least $220 per coil new pretty much anywhere. Rough times

[Ervin87]

Originally Posted by Bigjaybird

Where can I get the coil packs at the best price…

Search around. FCP Euro had them on sale for $225 each, last I checked.

[Bigjaybird]

Originally Posted by RocketyMan

Welcome to the forum. What EXACT coils and plugs did you put in? This is VERY important....

Thanks you guys have already helped a lot…