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**HO455** · 03-08-2024, 06:04 PM

The first thing would check at this point would be for cross firing between spark plug wires and or ground. There are a couple ways to do that.
One is to have the truck in a dark place then using a spray bottle mist water on the wires while the engine is running. The bad wires will arc and spark and you will be able hear and see the the flashes.
Or you can use an old school 12v test lamp with the alligator clip clamped on a good ground run the probe along the plug wires looking for sparks. This method can also detect cracks in the cap and around the coil output.

There are videos out there on both of these tests.

03-08-2024, 06:04 PM	#8
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 10,820	Re: 1998 c1500 4.3 misfire troubles The first thing would check at this point would be for cross firing between spark plug wires and or ground. There are a couple ways to do that. One is to have the truck in a dark place then using a spray bottle mist water on the wires while the engine is running. The bad wires will arc and spark and you will be able hear and see the the flashes. Or you can use an old school 12v test lamp with the alligator clip clamped on a good ground run the probe along the plug wires looking for sparks. This method can also detect cracks in the cap and around the coil output. There are videos out there on both of these tests. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F2 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377