Announcement

Collapse
No announcement yet.

SOLVED: M30 Spark on Cylinder 6 Only

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    SOLVED: M30 Spark on Cylinder 6 Only

    Hey guys,

    Just recently dropped my M30 into my 86 325e and only sparks on cylinder 6. Here are the details of the swap:

    M30b35 out of an 89 535i
    M20 "i" harness out of 89 325i plugged into ECU from donor motor
    New Bremi spark plug wires
    New Bosch ignition coil
    New NGK spark plugs
    Distributor cap and rotor used on my M20 for 5000 miles (relatively new and worked on the M20 perfectly)

    I tried to start the car for the first time today and the engine turned over, but only cylinder 6 fired. The car was getting fuel and compression. I tested each cylinder for spark by removing a spark plug and turning the car over to see if it sparked, only cylinder 6 sparked. I tested the other wires and they all fired when plugged into the 6th port on the distributor cap. I tried testing the distributor by using the one I removed from the M30, but the same issue persists. The distributor cap and rotor from the M20 and M30 have the same part numbers via RealOEM. I did not get a chance to try the old M30 rotor as I could not find it.

    I am thinking it may be the rotor not making contact with the cap for each cylinder (and only cylinder 6), but I am not sure why this may be. The issue may be something completely difference, I am completely stumped as I have never dealt with an issue where only one cylinder fires. Any help is greatly appreciated. If you need anymore information to help me diagnose, I will be happy to share.

    Thanks,
    jdance30
    Last edited by jdance30; 01-03-2018, 11:13 AM.
    1986 325e Pearl White on Grey Houndstooth 24x,xxx miles M30b35 Swapped
    2002 525i Jet Black on Sand Beige 13x,xxx miles
    "This 2.5 liter inline six cylinder is smoother than my silk Versace underwear." -Vehicle Virgins

    #2
    The issue has been resolved.

    After further diagnosis, it turns out the wires from Bremi were mislabeled. The wire leading from the ignition coil was labeled #6 at the distributor. Basically, the ignition coil was directly connected to cylinder 6. After switching the wires, the car started right up.

    I hope this helps anyone who might run into a similar issue. Although the wires are new, it doesn't mean the wires are good or labeled correctly.
    1986 325e Pearl White on Grey Houndstooth 24x,xxx miles M30b35 Swapped
    2002 525i Jet Black on Sand Beige 13x,xxx miles
    "This 2.5 liter inline six cylinder is smoother than my silk Versace underwear." -Vehicle Virgins

    Comment

    Working...
    X