Fuel starve, or something Options

[arsprod]

agree replace the condenser

Sounds more like an ignition issue because of the randomness. Could be sticking advance plate assuming you’re using a traditional mechanical distributor.

Ignition and fuel issues are commonly mis-diagnosed one for the other.

Otherwise not enough info in your post to be of much help. No mention if RPM’s and load when this occurs. No photos of plugs. Have you verified bowls are clean and free of debris? Checked the jets for debris / corrosion?

The jetting you have is a little bit non traditional (main smaller, idle larger) but should be capable of running consistently and reliably.

On the fuel side, are you sure you have carbs properly tuned for best lean idle and synchronized properly?

Really, condenser? Curious why

[Shivers]

agree replace the condenser

Sounds more like an ignition issue because of the randomness. Could be sticking advance plate assuming you’re using a traditional mechanical distributor.

Ignition and fuel issues are commonly mis-diagnosed one for the other.

Otherwise not enough info in your post to be of much help. No mention if RPM’s and load when this occurs. No photos of plugs. Have you verified bowls are clean and free of debris? Checked the jets for debris / corrosion?

The jetting you have is a little bit non traditional (main smaller, idle larger) but should be capable of running consistently and reliably.

On the fuel side, are you sure you have carbs properly tuned for best lean idle and synchronized properly?

Really, condenser? Curious why

.

The car runs great - and then it doesn't. With no consistency, it will start to stumble, cough, and backfire. Most of the time it works itself out though seems to be getting worse. I'm befuddled. confused24.gif

It was my first thought. Only because all that you mentioned happened in my 65 Tempest. I replaced the cap, the wires, the plugs and then the points. Still ran like (IMG:style_emoticons/default/stromberg.gif) An old guy I knew asked me if I replaced the condenser. A couple dollars after I threw so much money at it and it ran great. Should have with all the new parts. (IMG:style_emoticons/default/dry.gif)

[technicalninja]

Points and condenser should always be changed together IMO.

There's been a problem with modern aftermarket points not having decent plastic actuators/rubbing blocks and wearing stupid fast.

Like adjust points and 3 hours of use later the blocks had worn enough, and the points need further adjustment.

I use a dwell meter to adjust points.

Here's an interesting shop prank use of condensers.

You can charge them UP with a model train controller/transformer.
Once it's charged if you touch both the lead and the housing at the same time it will SHOCK you badly.

The bigger the condenser the bigger the shock!

You charge it up, toss it to a work mate saying, "Check this out" and human nature takes over.
We just can't resist touching the wire...

A workmate had a BIG one off of a Model A Ford.
He's gotten everyone in the shop with it at one point or the other.
He could CLEAR all the mechanics out of the break room by tossing it on the table.
A little electronic hand grenade!

[arsprod]

Points and condenser should always be changed together IMO.

There's been a problem with modern aftermarket points not having decent plastic actuators/rubbing blocks and wearing stupid fast.

Like adjust points and 3 hours of use later the blocks had worn enough, and the points need further adjustment.

I use a dwell meter to adjust points.

Here's an interesting shop prank use of condensers.

You can charge them UP with a model train controller/transformer.
Once it's charged if you touch both the lead and the housing at the same time it will SHOCK you badly.

The bigger the condenser the bigger the shock!

You charge it up, toss it to a work mate saying, "Check this out" and human nature takes over.
We just can't resist touching the wire...

A workmate had a BIG one off of a Model A Ford.
He's gotten everyone in the shop with it at one point or the other.
He could CLEAR all the mechanics out of the break room by tossing it on the table.
A little electronic hand grenade!

That's reason enough to get half dozen condensers! (IMG:style_emoticons/default/biggrin.gif)

[ClayPerrine]

Back in the days of carbureted cars, one of the older techs had a box that he could put on a dead distributor in place of the coil wire. Then he could start the car and move into the shop. Basically a Model T spark vibrator. The spinning distributor would break up the spark enough to get it to run. It ran crappy, but it beat pushing the car.

We had a mechanic who pulled the "throw a charged condenser at you" one too many times. So our older tech decided on revenge. He put a 12v battery under the offending guy's tool box, hooked the coil wire of the spark box to the back of the tool box with a pair of vice grips, turned it on, then used a push broom to push it under the toolbox.

When the offending tech came in later, he reached for his tool box and the sparks visibly reached out for his fingers. He tried gloves, rags, and anything else he could think of to move the toolbox to get to the spark box underneath. He finally resorted to a stick that he used to knock the alligator clip off the battery post.

He never threw another charged condenser at anyone again.

[technicalninja]

My Wall brand soldering iron will make an HEI module spark like crazy when you get it within 5 inches and pull the trigger.

I've never used it to move a car however!


"light up" the toolbox is GREAT!

Never seen that before.

I HAVE wanted to do that to a driver's seat ...

Probably best I wasn't aware how easy it could be done!