Re: inspecting spark plug wires
Posted: January 3rd, 2010, 5:36 am
I'll chime in a cheap old trick for spotting faulty plug wires. This trick wont tell you if the wires have the proper resistance.. but.. if you have plug wires arcing to ground causing misfires.. this will show you which one and where it is arcing. Wait till really late at night in a very dark place and open the hood while the engine is running. Wait for your eyes to adjust to the darkness and if there is any arcing it will be visible as tiny white pulses along the plug wires. This can also show a disty cap or coil that is arcing to ground as well. A pitch black garage works best.. just be sure you have it well ventilated when running the engine.
Another trick.. grab an inductive timing light.. clip it onto the plug wire you want to check as close to the spark plug as you can get the clip. While the engine is running.. pull the trigger and watch the strobe effect for several minutes.. (Not recommended if your epileptic) The flashes should be regular and consistent. If you see any "pauses" thats a misfire or the spark went to ground somewhere before it got to the sparkplug.
One last thing. When doing these checks.. make sure you have the gap set on your spark plugs correctly. If the gap is to wide, the spark is more likely to find a shorter path to ground. Current always follows the path of least resistance.
Hope this stuff helps
Tunes67
Another trick.. grab an inductive timing light.. clip it onto the plug wire you want to check as close to the spark plug as you can get the clip. While the engine is running.. pull the trigger and watch the strobe effect for several minutes.. (Not recommended if your epileptic) The flashes should be regular and consistent. If you see any "pauses" thats a misfire or the spark went to ground somewhere before it got to the sparkplug.
One last thing. When doing these checks.. make sure you have the gap set on your spark plugs correctly. If the gap is to wide, the spark is more likely to find a shorter path to ground. Current always follows the path of least resistance.
Hope this stuff helps
Tunes67