On my '48 GMC with a later model 228 engine. I have one of those visual spark testers where the plug wire goes onto one side of the tester and the other side of the tester goes onto to the plug. Using that, I found an intermittent weak spark on #6, the engine stumbling each time the spark showed yellow in color. I switched #6 wire with one of the other wires but the miss remained on #6. I compared the resistance of each of the spark plugs and #6 was much higher than the others. I also ohmed the wires and while they seemed OK I had a fresh set on the shelf so the truck got the new wires and also a fresh set of plugs.
The new wires and plugs have helped but the stumble is still there from time to time. Am I right in thinking that I should be looking at my distributor now? What am I looking for? Wobble in the shaft? Worn cam lobe? Other usual suspects?
Help is appreciated! Thanks, Jim
