Engine Missing At All Speeds Suddenly

F134 - All new everything running great with 100 miles on it so far. Today it started missing all of the sudden (over the course of a block). I tried adjusting the timing and air mixture screw at idle and that didn't help, I swapped plugs and plug wires, that didn't help.

Any ideas? I'm suppose to bring it to a car show tomorrow morning!

Help!

I was thinking I'd check the carb to see if it was plugged up or maybe the condenser? What could cause such a quick change?

 

Could be another case of condenser-itis. It's been bad this year.

Joking aside, put your old condenser back in. If that doesn't do it, try your old coil.

 

Is it missing on one cylinder, or all cylinders? Important to differentiate.

If all, check the points are both clean and correctly adjusted.

For some reason no one ever wants to do this, but it is absolutely fundamental BEFORE doing any diagnosis, tuning, or parts swapping. And certainly before timing, since the the point gap affects the timing. And it is extremely easy.

A bad condensor can quickly burn points, as will the wrong coil if it lacks a voltage reducing resistor.

 

Well, pulled the points and they were burned a bit and slightly off. Replaced, re-gapped and it's purring. I've never seen points go from hero to zero that fast. Crazy.

Question - I switched to resistor plugs and plug wires for the radio to work. Could that be a contributing factor to this issue? The coil is an internal resistor type from Walks also...

 

Like Pete stated, a bad condensor can cause issues. The new ones have been absolute garbage lately. I'd seriously consider putting your old one back in if it still was good. It will most likely outlast your new one even if the new one is currently good.

Doubtful.

 

The quality of the points and condensers are just junk now. Not uncommon to only get a few hundred miles out of them. Then you can happen on to a set that will run really well with no way to differentiate.

 

Also, if the coil is designed for an external resistor, but does not have one, points will degrade within hours.

Enjoy your car show.

 

Last question. Is it ok to run resistor type plug wires with non resistor plugs or vice versa, or should they always be run together?

 

You can mix and match resistor wires and plugs and it will not affect the running of the engine. The resistor plugs/wires are to eliminate ignition noise being picked up by a radio/stereo. Without resistor wires/plugs, you will get varied amounts of clicking or whining sounds on the radio.
-Donny

 

Closing the loop on this. It wound up be a bad condenser as suggested here. Thanks guys.

 

And carry a spare points and cond in glove box!
Ps- could we not use a condenser from a 4cyl of any type, maybe a farm tractor?
Or some kind of nos part instead of the new junk?

 

I think so - jeep used to have the same part number across many applications and years.

Someone posted here a few weeks ago about a high quality part that would cross over from another make.

 

In case you're wondering what one looks like inside....

This is what a bad condenser sounded like.