Missing on two...

This is why I don't prefer my dad using Willy when I'm not there. I've been off the farm for a few weeks, when I get back, he tells me the CJ is running bad.

Turns out, it is. Look's like I'm blind on #1 and #4 cylinders. The plugs are fine and clean, and I haven't historically had any trouble with the ignition system.

What I'm curious about is, could this possibly be out-of-adjustment valves? My Dart acted the same way this summer before I adjusted the valves. If so, what's the valve adj. procedure on these? Does the motor have to be running?

TIA

 

What does 'blind' mean? Are those two cylinders totally dead?

Valves rarely change adjustment noticeably or suddenly. But a compression test wouldn't hurt to do. Blown head gasket is also a possible cause, but not usually on those two cylinders at the same time.

However - First thing I would do is look at the distributor cap, rotor, and points. Clean, or replace, and set points gap.

Another possibility is bad HT wires. With the engine running take a look in the dark for misplaced sparks going to ground. Clean the porcelain part on all your spark plugs too.

 

1 and 4 ???? 1 and 4?? That is suspicious...

So, the straightforward and simple question that I'd have to ask is "have the spark plug wires been removed and reinstalled?

If you can't get a clear answer, then note which one is # four and which one is # one on the distributor cap and then swap those two wires and try it again. If that doesn't cure it, then swap them back to their "original" position before doing any other trouble shooting.

But an ignition problem suddenly appearing on 1 and 4 OR on 2 and 3 sounds like someone swapped a couple of the wires inadvertently.


Firing order is 1-3-4-2 COUNTERCLOCKWISE on the distributor cap.. Number one is "usually","normally" in the five or six o'clock position, but not always...

 

@PeteL, yes, those two cylinders are compeletely dead. The CJ sounds like a tractor, I kid you not.

Prior to it running badly, Dad swears he didn't pull any plug wires off, so I'm going to take his word for it.

As far as distributor cap and rotor, what to look for to see if they're worn out? I'm well familiar with points and the plugs are only a year or two old . I'll be putting new plug wires on today if all goes well, too.

 

Pull those two plugs and see if they are carbon bridged shut.

That happened to my '66 Olds 425 on a trip. Put in new plugs and made 4 hundred miles, then lost one cylinder. Suddenly had half the power and sounded like a tractor. A bit of carbon got into the gap area of the plug, and got welded there the next time the plug fired.

 

"As far as distributor cap and rotor, what to look for to see if they're worn out?"
Burning and/or oxidation crud on the metal terminals inside.

Also check for any moisture, oil. dirt, or cracks in or in the plastic that could be diverting the HT spark.

Is it possible the plugs are carbon fouled by excess oil burning, or rich mixture?

 

Thanks, PeteL...I'll look out for those.

AS far as plugs, nor...they look fine. 1 and 4 look just as clean as 2 and 3; definitely not visibly fouled.

 

You may have carbon arcing in the cap. Look for carbon tracks that look like cracks on the inside of the cap.