Crazy thought, but have you tried changing brands of gasoline?  Refiners are now blending summer grades, maybe something is different in the blend between refiners.

John - "The Hoosier Hurricane"

I have the same problem in my 71' demon. Taken it to two mechanics and they have NO clue what teh prob is.. All my stuff is Eddy BTW. I tried new plugs,carb(holley) etc. (even though there was less than 1000 miles on the rebuild)...after it passes a cetain threshold she's fine, but off idel til about 2400-2700 she sputters and sometimes will backfire thru carb or stall????

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic

Rods.  Did you disconnect the choke wire and rule that out?  Your description of the problem still sounds like its ignition related and voltage to the coil can still be the source of what you’re looking for.  It’s not unusual for an ignition system to slowly degrade until the weak link in the system creates problems.  Most of the time, reducing the spark plug gap and seeing an improvement in performance will point to a degrading or not up to snuff ignition system.

Lorena, Texas (South of Waco)

Since I have had such crazy and weird things go wrong (like a 2 cent washer) I will trace all the wires back and make sure all sound...



I WILL CONQUER THIS GREMLIN!

1957 Thunderbird

312

The carb was completely rebuilt in May so it should not be it but it never hurts to check.!

1957 Thunderbird

312

Now that you mention it, I remember the condenser post as well. I have an extra one, may as well try it out when I recheck the point gap... I checked the pump with the last round of problems and it was working fine (mechanical) Do not have another coil but might see about replacing it anyway.... Thanks

1957 Thunderbird

312

in my last post it should have been 56 cussy not a 52 cussy not looking at the keyboard does this to you not old a bit...........

    RAY. Y,S ALWAYS

rods just a thought a mate of mine had nothing but trouble with his 52 cussy couldn,t find out what was wrong with it in the end discovered that the engine mounts were to old and were moving causing the bolt coming out of the dizzy with the wire to the coil touching the fire wall and shorting the engine out making it miss every time that you started to drive faster

    RAY. Y,S ALWAYS

Hi, not sure what carb youre running but have you checked if accelerator pump is working correctly? worth checking among other things. Good luck. best regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Just a suggestion.Do you have a known good coil to try and the same with the fuel pump?I believe there was a similar problem with someone elses car back a few posts and turned out to be the condensor in the distributor.I would not touch the point gap if its at .015.Have you checked the point gap?