DIY ignition coil/plug wires replacement

[///m42 sport]

So I recently had issue with decreased throttle response, poor mpg.  This turned out to be a prob with one of the ignition coils.  I know theres the COP kit which cleans up the engine bay quite a bit, but I went the OEM route. I ended up replacing the plug wires, spark plugs, and one bad ignition coil.

part # of the coil I got.  I double checked with bma to make sure this was the correct coil for the 91 318is.

Its not exactly the same as the original, but you just pull the rubber hose off the bottom of this coil and it'll work the same.

Bosch plug wires
12 12 1 721 932

NGK BKR 6 EK
12 12 9 064 619

First off disconnect battery.



Then remove cover to access plug wires


Then pull the plugs off the ignition coil


Take the plastic cover off the coils


Undo the bolts and keep track of the washers!! Theres some hollow tubes that help the coils stack on top of each other.


Removing coil.  I only replaced one of mine.


New coil.  Doesn't exactly look like the original.  The sliding lock tab is upside down.  You could insert it the opposite way but that would require a dremel and I was lazy.


Install new coil


Tips: keep track of the order that you remove the wires.  I know the OEM wires are numbered but the new set that I bought was not.

Idles perfect now! Also much improved throttle response.