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5gm
10-14-2005, 02:00 PM
hi,
can anyone help.
i have a 98 m3 evo (S50) which has an intermitent missfire at high rpm when on full throttle, it normaly starts at about 5500 rpm & sometimes it will not rev above 6000 at all.
i have pluged in my scanner to check the fault codes & it comes up with missfire at coil cyl 3 & 4 (codes 24 & 50). i then tryed swaping the coil packs from cyl 3 & 4 with 1 & 2 to see if the fault changed cylinders but it stil says 3 & 4.
whenever i clear the fault codes it will not missfire at all for a few days & then it will do it randomly.
any help would be apreciated.
thanks
EricP
10-14-2005, 02:30 PM
If not coil packs.. plug wires?
AthleticTrainer
10-14-2005, 02:34 PM
I say the same, its more unlikely to be the coil, its probably 1 or 2 misfires, not all of them. Are your wires aftermarket? (MSD 8.5mm wires) I did this before with an external coil on my civic, and it wore out the wires and started to misfire. Could be that or the plugs at 3 and 4? it if says coil, the only thing I can think of is the rotor wheel in the distributor cap. it could be corroded and need replacing to get the full potential. -- Just an idea.
5gm
10-14-2005, 04:48 PM
hi,
this engine has a coil for each plug & as i said i have moved them around but the missfire is stil on the same cylinders.
Scotth
10-14-2005, 04:53 PM
Fuel injector problem??
OnlineAlias
10-14-2005, 05:03 PM
I say the same, its more unlikely to be the coil, its probably 1 or 2 misfires, not all of them. Are your wires aftermarket? (MSD 8.5mm wires) I did this before with an external coil on my civic, and it wore out the wires and started to misfire. Could be that or the plugs at 3 and 4? it if says coil, the only thing I can think of is the rotor wheel in the distributor cap. it could be corroded and need replacing to get the full potential. -- Just an idea.

Wow, just, wow....:clap
AthleticTrainer
10-14-2005, 05:33 PM
Wow, just, wow....:clap

LoL.. thanks. :cool
just comes with the experience I guess.
AthleticTrainer
10-14-2005, 05:51 PM
hi,
this engine has a coil for each plug & as i said i have moved them around but the missfire is stil on the same cylinders.

Yea thats right I forgot most bmw's have individual coils, then it could be the plugs. take em out and take a look. replace the plugs. Could be running rich and then it'll plug up the plugs. Have you looked at them lately?