Thump, Thump, Thump. That's the sound of my head banging against the hood of my 81 straight 6 because I can't figure out why it's missing spark. It has just enough of a sparatic spark to keep it running, but shows no consistency. Numbers 5 and 6 won't fire at all. I've replaced: plugs, wires, distrib cap, rotor, stator, jumped the wires back to the ignition module, replaced ignition module, swapped out the coil and checked the timing, which is roughly close to where it's supposed to be. One interesting thing is that when I put my timimg light on the coil wire, it's sparatic too, so the problem seems to be prior to the distributor cap. What the hell is wrong with this thing?

Now this truck (to my shame) is a poorly maintained beater. It needs a carb rebuild and and probably a lot more, but it has always been dependable enough to earn it's keep in my driveway. Please help an ignorant slum who loves his old junker.

 

Bovine ,
First make sure you have the spark plug wires in the correct firing order 153624 with a clockwise rotation of the distributor . Its very possible that the distributor needs replacing ? Verify that you get continuous spark to to the dist . Its always important to keep spark plug wires seperated with the plastic wire looms .
Paul

 

Paul,
When you say the "distributor may need replacing" what part exactly are you speaking about? I've replaced everything except the actual stem and I'm trying to get that out of the block next. I've removed the bolt and washer that snugs the distrib. in place, but can't manage to pull it out and my Haines manual isn't giving me any clues. My thinking is that perhaps the gear that attaches to the cam is chipped or somehow damaged.

 

I changed distrubiters on my truck when I put the new engine in it, getting it out of the old engine was a bit of a problem, it required a little bit of persuasion, make sure the shaft can turn, as it has to turn backwards, if not it will never move.

Paul, the 300 doesn't have them plastic clips, the wires aren't long enough to need them.
Evan MacDonald