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I suspect that at times I'm not running on all cylinders.  Its hard to tell, though.  The motor sounds about the same regarding its "throatiness."  But there seems to be a reduction in power - particularly noticeable when trying to accelerate up a hill in 3rd.

Can someone tell me the process for testing?  Do I pull over, keep the motor running and pull and replace the sparkplug wires one at a time to listen for an engine sound change?  Is there a shock potential here or is that spinning fanbelt my biggest worry?

Thanks in advance,


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Disconnecting them at the distributor end is safer. No heat. The wire has no spark going thru it  if. it's disconnected  from the distributor and the spark will seek grounding to the wire when it comes in close proximity again rather than your hand.  Suggestion....loosen all the wires at the cap first before doing the test. Sometimes they can be real hard to pull out.........Bruce

An update.  I have pulled the plugs at various times.  Everything seems fine.

I do notice a sound (pitch?) change and a slight loss of power sometimes during a long or hard drive.  Have pulled over and pulled plugs to check.  Seems OK.

I am beginning to wonder whether I should change the plug wires.  I've basically had to change everything else provided with this car.  Why stop now?

I realize that I could have a coil issue but I'll address that separately.

Thanks to everyone who has provided advice on this.


What distributor are you running? Have you checked/lubed it lately?

SVDA dizzies are notorious for poor running (which is why most people binned them in favor of mechanical advance 009’s BITD)  Mechanical advance dists also have issues if the springs are weak or if they’re improperly lubbed and sticky.

If you have an electronic ignition, they have their own set of issues.

But a new set of points, rotor, cap, wires and plugs is a good place to start. Even if you have an LX ignition, the spark is still transmitted via cap, rotor, and wires.

As for coil, it’s easy to check, AFAIK, there’s no such thing as a “weak” coil. It’s either in spec or it’s not.


“Another test for the Bosch Blue coil, is to use an Ohmmeter and with all the wires taken off the terminals of the coil attach the positive and negative, red and black, wires of the meter to first the terminal 1 and 15 that are printed (stamped) on the coil. You should have a reading of at least 3-4.5 ohms, which is the resistance reading inside the coil. A bad coil will show a higher reading then 3-4.5, you want less resistance. Next, place the red or black lead from the meter to the center of the coil (secondary post), and to either one of the terminals, again 1 or 15 on the coil. You want 9500-10000Ohms, sometimes you'll see less, but you don't want to see something like 11,000. Or if you have no reading in either case, the coil is trash.”

Last edited by dlearl476

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