Looking for some input...<RESOLVED!!>

[Slowleak]

Check your vacuum advance diaphragm. Mine dried up and cracked. You get a vacuum leak and it throws the timing off. How about your accelerator pump? Is is squirting gas into the carb like it should?

 

[Action]

Accelerator pump diaphram

I just replaced mine...Accelerator pump diaphram...our great gas eats them up. Yes check for vacuum leaks everywhere.
jack

 

[jckkys]

Early Broncos don't have fuel filter at the tank, only a screen on the fuel pick up in the tank. A filter between the fuel pump and carburetor is all you'll ever need. The whole sale replacement of parts with no diagnostic indication that that's what's wrong, is no way to save money. Your mechanic should have a scope that will immediately identify a misfiring cylinder or cylinders if ignition is the problem. He can also diagnose the presence of a vacuum leak. With a competent diagnoses you can do the needed repairs. In time you'll learn to do your own diagnosis.
A dwell meter is just one function of an engine analyzer, that also has a volt meter, amp meter, tachometer, and measures resistance at the points, all for about $20 on ebey. I use a Sears Craftsman unit that's 40 yrs. old. A vacuum gauge and timing light are also a good idea. If the carburetor is the culprit, get a rebuilding kit and go through the carb with the instructions and replacement parts on hand. All these are better investments than new parts you likely don't need.

 

[g8rb8t]

Thanks for the advice. All the thinks I've done to date were on my tune up list. Replaced the points today (previously just gapped them). Almost giving up on it now. Only thing I can think of is carb needs rebuild (tuning after timing took about 4 turns out to get it to run smooth) vacuum leak, or timing chain. Only replacing the hard vacuum lines that are no longer flexible is on my list.

Don't think I've got the appetite for carb rebuild or timing chain. Like you said, probably need diagnostic help at this point anyways.

 

[g8rb8t]

Well I conceded this morning that I need some more help. Got the vacuum lines replaced and still the same issues.

The Carb idle air screws would only run with 4+ turns out from seated. So runs but very rich (which leads me to believe vacuum leak somewhere)??

Thanks for all the input, I'll report back with what they find.

 

[g8rb8t]

Heard from the shop and I'm up and running again. I was on the right track....

- Removed Carb and blew it out
- Reset timing to 6 degrees
- Reset Points gap
- Replaced condensor in distributor

Guess all the other stuff I did was maintenance at least!