GM pickup coil and ignition coil mismatch

AL8001 at aol.com AL8001 at aol.com
Tue Oct 20 00:49:00 GMT 1998


In a message dated 98-10-19 18:54:07 EDT, twsharpe at mtco.com writes:

>Robert Wilkinson wrote:
>
>> Just read a little blurb from a service manual:
>> "Ingnition coils with Red and White leads should be matched with pick-up
>> coils having either a Clear, a Black, or a Blue connector.  Ignition coils
>> with Red and Yellow leads must be matched with pick-up coils with a Yellow
>> connector."
>>
>> Mine don't match, and I'm trying to trace down a high rpm miss.... think I
>> am on the right track??
>
>

Ez.  The different pick up coils are for different distributor rotations.  The
GM 4 pin module ( probably others) trigger on the falling edge of the AC sine
wave generated by the pick up coil. 

 If you mix pickup coils the timeing will be off 45 deg on a V8.  No problem
you say, just turn the dist so the spark fires at the right time.  Well the
rotor phaseing is now off, the rotor is pointing between the plug wire
contacts.  This causes lots of spark scatter.


Harold



More information about the Diy_efi mailing list