The Ford Barn - View Single Post - Who Can Diagnose THIS Total Mystery? Win A Prize?

Tom Wesenberg · 01-27-2013, 03:52 PM

The next time it acts up don't touch anything. Just shift to neutral, and let it coast to the side of the road. Then lift the left side of the hood and hold the coil wire 1/4" from a head nut while you push the starter rod with your right hand. Good blue spark, then you must have a fuel problem. Poor yellow or no spark, then don't mess with the fuel system but check the switch and cable leading to the distributor, and the short wire between the upper and lower plates.

My car was backfiring bad a few years ago, and it was very intermittent. One day it was starting to act up and I noticed that as soon as I touched the key on the repro switch the engine shut off. The weight of a small key fob swaying back and forth was sometimes enough for the poor switch contacts to not make. I removed the back cover on the switch and improved the contacts, so they now have a much better positive click when turned on.

01-27-2013, 03:52 PM	#45
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Who Can Diagnose THIS Total Mystery? Win A Prize? The next time it acts up don't touch anything. Just shift to neutral, and let it coast to the side of the road. Then lift the left side of the hood and hold the coil wire 1/4" from a head nut while you push the starter rod with your right hand. Good blue spark, then you must have a fuel problem. Poor yellow or no spark, then don't mess with the fuel system but check the switch and cable leading to the distributor, and the short wire between the upper and lower plates. My car was backfiring bad a few years ago, and it was very intermittent. One day it was starting to act up and I noticed that as soon as I touched the key on the repro switch the engine shut off. The weight of a small key fob swaying back and forth was sometimes enough for the poor switch contacts to not make. I removed the back cover on the switch and improved the contacts, so they now have a much better positive click when turned on.