C2 - Weird Distributor Problem

[Sean L.]

I have a 64 327/365 roadster that engine's acceleration and general "smoothness" has deteriorated over the last 3 months. I pulled the plugs and discovered that three were fouled. I then ran a compression check and all cylinders held 150 PSI +/- 5 PSI. After that I decided to eliminate the spark plug variable, so I replaced the plugs and wires, but to no avail. Then I realized that if I pulled these three spark plugs wire off of the distributor cap while the car was running, there was no drop in RPM, nor was there a small spark arcing the connection like in the other 5 wires. Of note I have 12V at the coil, the disributor is original and these 3 suspect wires are all on the same side of the distributor cap.

So my conclusion is that 3 cylinders have no spark (hence the spark plug fouling) thus resulting in poor engine performance. Today I replaced the distributor cap hoping for an easy fix, but again to no avail.

Any idea of where to go from here? Should I punt and go for a breakerless conversion kit?

Thanks for the help
Sean

[Tommy F.]

Re: C2 - Weird Distributor Problem

Is it possible that they (the wires) are out of order?

If the cap and wires are in good shape, pretty strange that you get 3 dead holes that are on the same side of the cap.....

[Jim D.]

Re: C2 - Weird Distributor Problem

Try Replacing the plug wires

[Clem Z.]

Re: C2 - Weird Distributor Problem

Try Replacing the plug wires

he did replace the wires BUT i would check them from inside the cap to the plug end with a ohm meter to see if you have continuity and check the cap for cracks or carbon tracks

[Timothy B.]

Re: C2 - Weird Distributor Problem

If the wires and check out look at the weight base cam inside the distributor and see if the point opening lobes are wore thus no opening of the points enough on these cylinders to make coil spark.

[Sean L.]

Re: C2 - Weird Distributor Problem

Thanks guys...I replaced the cap this morning with a new one, but unfortunately it didn't fix the problem.



Thanks again,
Sean

[Harry S.]

Re: C2 - Weird Distributor Problem

This is going to sound strange but I recall this being discussed several years ago. The problem best I can remember was the ballast resistor.

Harry

[Timothy B.]

Re: C2 - Weird Distributor Problem

Sean,
Put a timing light on the suspect wires to see if they are firing with the engine idling, let us know what you observe.

[David T.]

Re: C2 - Weird Distributor Problem

It's easy to damage plug wires when trying to route them through the ignition shielding or maybe the new wires were just plain defective. You can check wire resistance with an ohmmeter. I think I'd try 3 known good wires (maybe even the 'good' wires from your old set.) Route them over the valve covers temporally and see what happens. A weak coil or bad resistor can play heck with your spark too. With a new cap, rotor, plugs and wires it should just spark like mad. Good luck!

[Sean L.]

Re: C2 - Weird Distributor Problem

I checked the resistance on all new/old spark plug wires and they were all the same. I also tried using known good wires to see if I could get a spark on the three suspect lines. But regardless of the wire used, the three same connection didn't have a spark. So far I've replace the plugs, wires and distributor cap. I just ordered a new rotor, points, condenser and ballast resistor. Any other possibilities during this process of elimination?

This small problem is preventing me from taking the car out this summer...disappointing.

Thanks for all the help.
Sean

[Tommy F.]

Re: C2 - Weird Distributor Problem

18436572....Check the firing order.

[Cecil L.]

Re: C2 - Weird Distributor Problem

I'm sure this is not your problem but just to illustrate how weird some of these things can be, I bought a 64 Impala convertible a few years back and got a good discounted price because of an engine miss that the seller could not seem to correct. I did the usual trouble shooting and found the #3 and 4 cylinders not firing. I changed plugs, points, wiring etc. to no avail. I finally pulled the valve covers and .....surprise, the intake pushrods were missing from #3 and 4 . Not being able to imagine any logical reason for this, I checked the oil filter and in the pan for any evidence of pieces of gound off or broken pushrods and everything was clean. Satisfied that it was unlikely that the pushrods were broken off and lying in the lifter galley, I installed 2 new pushrods and everything was back to normal. For the life of me I just can't imagine why anyone would intentionally leave out those pushrods other than some misguided attempt to save gas by making a 6 cyl out of a V8.

[Sean L.]

Re: C2 - Weird Distributor Problem

Gentlemen,

Outstanding news. I just finished replacing the condenser, points, and rotor cap and I'm pleased to report that the entire problem is fixed. In fact the car is now accelerating incredibly smooth. To be honest I had no idea that was how the car is supposed to drive. Anyway, thanks Tommy, Jim Clem, Tim, Harry and David for the help. I couldn't have done it without you.

Sean

[Randy S.]

Re: C2 - Weird Distributor Problem

Sean,
Great news thanks for closing the loop. I was curious about this one. Especially after replacing the distributor capto no avail. I would never have guessed points, condenser and rotor.
Anyone have a theory why points, condenser or rotor would only effect 3 cylinders?

[Alan D.]

Re: C2 - Weird Distributor Problem

Do you have 12V at the coil when running??? Think that's supposed to be 6-7V ? As Harry said "The problem best I can remember was the ballast resistor." Just asking! Do not know for sure about what the voltage SB.
Second idea, is it a TI distributor which does have 12V at coil.