1228746 TBI 305V8 stumble

[Jay Vessels]

Hi there!

>Does the CCC distributor have a vacuum can on it? If so, you may have the 
>retard only distributor. Im not that familiar with those year cars but you 
>may not be getting any timing from the ECM, only the retard signal. This is 
>just a thought. If you are using an 8746, you need the correct ignition 
>module so that the ECM can control timing. Look at www.customefis.com in the 
>DIY section and you'll see how to make any HEI distributor a computer 
>controlled unit.

There is no vacuum to the CCC distributor, and no weights/springs.  On
Dad's '86 caprice, we used his CCC distributor in the TPI conversion.  I
forget why (probably one less unknown since they were both big-cap HEI).
Worked fine.  

As far as electronics go, I thought the only two HEI distributors GM had
were either mechanical/vacuum advance, or ECM-controlled.  Are there
different flavors of the ECM-controlled HEI (besides internal or external
coil)?

When we have the bypass wire disconnected (to set the timing) we can set
the timing wherever we want, within reason.  Plug the bypass wire in with
the base timing set to 0 and we see 12 degrees or so at the balancer.  I
haven't tried rev'ing the engine to verify the advance changes (next on the
list).  I assume this means the advance circuitry works? 

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1994 Chevrolet Cavalier Z24 Conv., 3.1V6 MPI


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