Engine misfires on B bank,,

[Sasha]

Hi there,

V12 HE, engine misfires on B bank,, any ideas??

regards,

Sasha,

[Brakebuster]

hi,

probably the coil for the B bank spark plugs, they do break down

best way to test it is swap it for the A bank one and see if the misfire swaps sides with it,

does it only do it when the engine has warmed up ? if so , then it will almost deffinatly be the coil

hope this helps

BB

[davidr]

How old is the car? If it's 1989 or later it will have the Marelli ignition. You can identify this by the distributor cap being smaller than the older ones with 2 rings of 6 leads instead of the old one having one ring of 12. It also has 2 square coils on top of each other instead of cylindrical ones.
If it is Marelli ignition then one explanation is that the carbon contact on the top of the distributor rotor has worn out so that the one side does not get any spark at all. This is quite common and often the cause of engine fires on cars with catalytic converters.
The Marelli ignition system effectively works as two 6 cylinder systems although they both go through the same distributor. Check the coils, HT leads and the amplifiers on the radiator top rail.
If your car has cats DO NOT run it with any kind of misfire - or have a fire extinguisher close to hand!
Of course, if your car does not have Marelli ignition all of the above is a waste of time!!
Good luck and hope this helps!!!

[davidr]

Sorry - forgot to say that one good part about it being 2 separate systems is that you can swap bits like coils, leads, amplifiers etc to test them!