Engine Missfire

[mantta]

I noticed the last few years that I have a missfire that is unsteady after driving 30-40 miles. I have checked everything and today I noticed something I never thought of. My distributer has the aftermarket armored cable going to the ignition switch and it is not grounded to the cylinder head bolt like the original ones because it is much smaller in diameter. My distributer does not fit real tight in the head, it will wiggle a little but not anything of concern. So, I was thinking that the only ground the distributer has is to the loose connection to the head and it's drive shaft. I took a digital ohmmeter and read the resistance between the condensor ground and the engine and it read 4 ohms. Ahh, now the question, what is a good way to ground this cable or distributer?
Thanks!

 

[BILL WILLIAMSON]

mannta,
The distributor locking bolt should be a sufficient ground and some grounding is accomplished through advance control rod. Put a jumper from dist to block and see if you still get 4 ohms, that's not really very much.
In the dark, see if you have any arcing from the top of dist cap to plug straps. The wire buried in the cap to #4 would arc out to my #3 connector strap at times. I put a skinny wire from #3 at the cap, up in a HIGH loop to #3 and it purred for a month 'til my new cap came. Bill W.

 

[Tom Wesenberg]

Just run a wire from the condenser ground screw to another good ground such as the coil mounting screw.

I've seen a couple distributor shorts the same as Bill just mentioned.