Ignition Grounding

Moderators: 330GT, abrent

Post Reply
John Vardanian
Posts: 1906
Joined: Wed Sep 04, 2002 12:13 am
Location: San Francisco Area

Ignition Grounding

Post by John Vardanian »

I have rebuilt my distributors and tested them on the machine, all was good. On the car, there appears to be an intermittent loss of ground on the whole bank. The car's missing coincides with the strobe light skipping beats. I have a decent jumper grounding the distributor, but still. Is the distributor grounded via the three hold downs? Any ideas what's going on? Thanks.

john
PF Coupe
DWR46
Posts: 621
Joined: Tue Sep 22, 2009 8:23 pm

Re: Ignition Grounding

Post by DWR46 »

John: The three studs on the distributor drive are the ground path. Make sure the nuts are tight, otherwise, you have a internal problem in a distributor.
User avatar
tyang
Posts: 4060
Joined: Wed Nov 27, 2002 10:28 pm
Location: New York
Contact:

Re: Ignition Grounding

Post by tyang »

Hi John,

It may not be the ground, but the ignition wires may be grounding out. Check to make sure the spade connector for the points are not too close to the body of the distributor. I've seen these arc to ground instead of through the points. I bend them out a little to make sure there is enough space between the wires and the ground path. Also make sure the plastic insulator is properly centered in the body of the distributor.

Good luck.

Tom
'63 330 America #5053
John Vardanian
Posts: 1906
Joined: Wed Sep 04, 2002 12:13 am
Location: San Francisco Area

Re: Ignition Grounding

Post by John Vardanian »

Since we're all learning here, I'd like to report on my ignition woes. I thought the distributors weren't grounding well, so I ran hefty jumpers from both distributors to a good ground source. Problem persisted. Then after a while I realized the problem was on one bank. I loosened the distributor cap screws of that bank and jiggled the cap and problem intermittently self corrected. Then I checked the insides of both caps; no evidence of fault. Then I came up with a brilliant idea that only an equally brilliant mind can conjure, I swapped rotors (left to right). The problem went to the other bank. Bingo! Close inspection of the rotor showed a hairline crack.

Tom, thanks for the tip about the points springs grounding. Having gone thru that pain already, I have insulated the springs with nylon cover; covered them with electrical wire shrink tubes.

john
PF Coupe
Post Reply