Which specific 3 cylinders are not firing?
Are those 3 cylinders
completely dead?
Does it sputter/pop/backfire/fart/belch?
Are the plugs on those 3 cylinders fuel fouled, or clean?
Depending on the answers to the above questions, I would be leaning towards an ignition issue, assuming the compression is right in all of the cylinders. The pole piece/pick-up coil in the distributor could cause goofy stuff like this, as could the ignition module itself. I have also seen HEI rotors that would kill some cylinders, but not all.
And...."new" don't mean JACK....ever had a new light bulb that blew as soon as you turned the light on?
It may well turn out to be a problem with the cam, but if so, it should be backfiring or something, and it would have to be an even number of cylinders not firing, if it had the incorrect firing order. I wonder if he wound up with a cam for a Marine application? Some marine engines run backwards, and the cams are ground accordingly, but the teeth for the distributor gear would be "correct".
This is one of those absolutely frustrating situations, where you've checked everything that makes sense to check, but there's no hope in sight. That's when it's time to start checking stoopid stuff...like plug gaps.
|UPDATED|8/3/2012 10:02:55 AM (AZT)|/UPDATED|
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Joel Adams
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