Today, while continuing to track down the source of my 235 idle and
acceleration hesitation/ miss, I was checking the timing using a timing
light. Previously, I had used my vacuum gauge and my ear to set timing. I
was using a Sears induction light. Anyway, I noticed that the light did not
appear to be flashing all the time, missing a flash now and then at idle. I
of course had it hooked to #1 cylinder for the test. My first thought was
that the timing light was malfunctioning. I hooked the light to my 97 S-10
V6 and it never missed a flash, so the light was good.
Back to the 235. Same thing and when I revved the gas, the timing light
skipped a few more flashes that coincided with the hesitation. I moved the
indication pickup to each plug wire to see how each responded. #2 flashed
each and every time, #3 only flashed about half the time, etc. After
checking all the plug wires, it dawned on me that if no current were flowing
thru the plug wire, (meaning the plug isn't firing) then the timing light
won't flash. I went and got a new set of plugs, but since I was late for a
wedding, I haven't had a chance to install them to see if the idle/run
problem is fixed.
What I wanted to share, is that your timing light can be used for more than
just timing the engine. Use it as a troubleshooting aid to see if each
cylinder is firing consistently as it should. Try it out next time.
Mike Klepp
'48 3100
Wichita Falls, TX
PS Doug and Bill, your patches are on the way.
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|