@bing I know the feeling been there did that it was on an old briggs that had the metal strap that grounder the plug to stop got zapped one time & always used a stick after that.
Could have been worse. A few Car Talk programs ago a caller said he ran out of water for his leaking truck radiator in the middle of nowhere, so he opened the hood & stood up on front bumper ⊠and ⊠well, you know. Then the next week a Professor from one of the local Boston Universities chimes in, explains it wasnât a good idea to fill the radiator that way. Dangerous. The Prof goes on to say that particular liquid has salt in it, and therefore conductive. The Prof says if the caller had accidentally missed the radiator and hit the battery terminals, well quite a shocking result.
I was thinking as I listened to the Profâs caution âHey, the battery is the least of his worries, what if the engine was running & missed the radiator and hit the ignition coil?â ⊠lol âŠ
OK ten characters.
db4690, the shop used a handheld tester of some sort which was rectangular, had a row of LED bulbs running the length of the rectangle and it had 3 leads or wires. One wire clipped to the batter negative terminal, another to the positive. The third wire clipped over the individual spark plug wire. If the LED lite green, the wire/firing was supposedly ok. All 6 of my wires/firing showed ok with their instrument - which was not the case.
GeorgeSanJose, I refer back to the documentation which gave me the instructions on how to do all these tests. The author insisted that the spark test be done with a HEI spark tester. He even made reference to the fact that if you check for spark the old fashion way (removing the spark plug from the engine and grounding it) you would be sorry.
The HEI spark tester has an alligator clip built-in which can be used to ground the tester, however, the author instructed to use a battery jumper cable, which I did.
In testing each spark plug wire, the HEI spark tester was extremely active and gave off a ton of sparks. When I got to the bad plug (due to the coil tower being bad) the spark tester basically did nothing except giving off one spark about every second or so.
I did not verify it because I had no reason to, but I would not be surprised had I just taken the plug out of the engine and grounded it against the engine, I would have got a spark and thought the firing was ok. Might be wrong but that is what I think.
Never thought of it before but grounding a plug with a battery jumper cable works great. The HEI spark tester has an alligator clip built-in but the jumper cables work great.
Yeah, it can be difficult to impossible to connect a small alligator clip to the battery post sometimes. So using a big-jaw jumper cable does indeed make a lot of sense. Thanks for taking time to post what youâve discovered, will help a lot of folks looking for advice here I expect.