e39 540 CEL

[Hypr5]

Hey guys,

I know this is mainly an e34 forum, but I finally made the jump to an e39 540. I know the cats need replacement, I bought it knowing this... however whenever the car gets in the upper rpm range, I get a CEL - The OBDII scanner says: Cylinder 2 misfire detected.

I cleared it once, it stayed away for a while, and now that I went back into the upper RPMs, it's back. Same code.

Does anybody know of a probable cause? Would a bad coil cause a misfire only at the upper RPM range? Could this be cat-related?

Any and all advice / comments would be greatly appreciated.
Thanks!

edit: is it possible that a generic scanner is reporting an improper code?

[azale]

I'm not sure how similar the ignition systems are, but I had this problem on my '03 Land Rover (V8, wasted spark, 2 coil packs [shoved so far behind the engine not even Mr. Fantastic could get to them]). I'd clear the codes and it would be fine in idle, but once I got it up to speed on the road it would say a cylinder was misfiring.

Changing the plugs didn't help me, and when I was changing the plug wires the old ones all tested fine for resistance. But when I was all done changing the wires, it never gave me another problem.

Let us know what it is once you figure it out.

[Jon K]

Switch the coil packs around, move #2 to #8 or something, then see if you get a misfire on #8

[Tiger]

Great idea.

[632 Regal]

a weak spark will blow out at higher rpms, could be a coil or simply a fubared spark plug.

[Hypr5]

Thanks for the advice..
does anybody know how i can identify which is cyl #2?

[Jon K]

I think it goes 1 2 3 4 front to back on pass side, 5 6 7 8 front to back on drivers side