Backfire and Hesitation

[lilm38]

The profile location is incorrect but I haven't updated it. Should be Edinburg. Jeep is stored in Corpus. I'm heading up there tonight so should have some updates.

[lilm38]

Ok, in reference to previous replies, upon preliminary examination, the spark plug wires are correct as shown in Wes' wiring diagram and PCV valve is plumbed properly. Is there something I'm missing in that regard?

[4x4M38]

It’s not uncommon to find the pcv valve installed backwards.

[wesk]

Main key in your post is that she ran fine until last week. You've indicated you did no mechanical repairs, replacements or adjustments that would have caused the change in behavior. So I think we are now down to waiting for your tests results.

1 - Vacuum gauge readings at idle, acceleration and 2500 RPM.
2 - Fuel pressure reading at carb inlet fitting.
3 - Compression test results.
4 - Leak down check results.
5 - Actual timing behavior static and running.

Anymore guessing at this point is simply guessing.

[RonD2]

In a post back on page 1 he said the last thing he did before the problem surfaced was replacing the Voltage Regulator.

[wesk]

Yes, I caught that but he said the regulator change was before the rough running started. If the regulator caused it by severely over or under charging he would have seen the issue on his amp or volt meter and mentioned it.

Main thing now is getting a very good and thorough diagnosis of the jeep's current operating conditions/parameters.

[lilm38]

It's been over a year and I thought I'd post an update on this issue as its finally solved. After I tried all the suggestions given here and had no joy, I sent the Carb and fuel pump out to be professionally rebuilt. Not cheap either. Then things got a little busy here on the Southern Border so I didn't have much free time to go to Corpus and install the rebuilt items. Finally got a day to get over there and found my nephew had moved into the house where the jeep was garaged and stored a mountain of his crap in there. I managed to make a path through it and installed the carb and fuel pump. No change from before and just had time to get back to Edinburg.
In December got reassigned to the HQ in Austin so went to Corpus, attached a chain to my tow hitch and the pintle hook and pulled the Jeep along with a pile of my nephews still unmoved crap,out of the garage, then towed it up to Bertram where a guy has a shop that works on all types of MV vehicles. Eventually got it back running perfectly.
Problem was this: The carb rebuilder installed the wrong size and gauge springs in the carb. Rebuilt it with correct parts and no problems.
Didn't mean to ramble for a one line answer.