Re: more DIS questions

[bearbvd@cmn.net (Greg Hermann)]

>Your term maverick, I don't understand, requardless thou, some DIS and ecm
>combos are for SEFI, and they need the cam signal.
>  ie Buick turbos.
>Grumpy

Wasted spark (also called maverick spark) designs fire every plug every 360
crank degrees. Once when each is supposed to be fired, and once near TDC on
the overlap. The spark on the overlap is what is called the wasted, or
maverick, spark. Since all plugs fire twice per four stroke cycle, cam
position doesn't matter.

The circuit for the spark on these comes from the engine (ground) up
through one plug, through that plug's wire, into the coil through one
terminal of the coil, through the secondary of the coil, out the second
terminal of that same coil, through another wire, and to ground through a
second (360 degree off, other side of the firing order) plug. Yep---each
spark has to jump TWO plug gaps. And yep--out of each pair of plugs, one
fires up from ground, and the other fires down to ground (opposite
polarity).

Agree that  for an ecu running SEFI AND a wasted spark DIS, cam sensor is
needed for getting the triggering of the injectors timed right. But--for
DIS ONLY--no cam sensor needed.

Greg
>
>
>| >Why can't you just bolt a disk with the proper notches onto the harmonic
>| >balancer for crank trigger and use the HEI distributor for cam trigger?
>| >Hang on, I not ready for the punch.....
>| >Terry
>| With a wasted (maverick) spark DIS set-up, no need for a cam trigger.
>| Greg