Still fighting this problem, Revs drop to zero if car not held at 1500 rpm.  I have plenty of volts, have tried my spare carb, looked at the distributor wiring.
No difference.  292 w/points, alternator conversion (happened before and after conversion. As an aside, I bought the alternator conversion off ebay.  It is a good installation, but the directions could be more specific (or perhaps I could be smarter...). A well spent $189.  Any ideas would be appreciated.

Sounds like a big vacuum leak.  I take it this problem happened after some change to carb or ignition.
Are you running with PCV?
Not likely an alternator problem as the ignition would operate on the battery.

"Still fighting" implies an ongoing problem.  What have you done so far?

Which carbs?
Which distributor?
Is the timing advancing properly?
How old is the crankshaft damper?
Do you have vacuum leaks?



Lawrenceville, GA

No vacuum leaks. Holley 2bbls, replacement was fresh rebuild, Ford distributor, don't know about the age of the damper.  No PCV, has a road draft tube.
I have a spare rebuilt distributor, I guess that will be next. My mechanic skills are not getting better with age and the distributor is difficult to get to on my Ranchero.
This problem came on suddenly, car was running great one minute and not the next. Thanks for the input!

Failure of distributor diaphragm integrity can result in a sudden vacuum leak, but not sure how that might relate to your problem.

6 VOLTS/POS. GRD. NW INDIANA

Have you checked to see if all the plugs are firing.   Maybe pull the valve covers to check all push rods and rockers.  Check valve lash.  Have you tried to spray stuff around the intake and carb to see if a vacuum leak.  Check the vacuum lines  - sometimes there is a small crack you can't see if the lines are in place.

Had a bad idle that drove me nuts.  All the lines looked good.  One day I happened to hit one line and it fell off.  Found it cracked, replaced it and everything was good


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Thanks for the replies!  It did run before the carb swap.  I have a hard line from carb to distributor for advance, no other vacuum leaks.
It is a violent stall below 1500. It's difficult to describe, but it's like the engine loses all power. Above 1500 it runs pretty smooth.

If it ran before the carb change thats tells you something. I saw a similar situation on a friends car not long ago. Who ever rebuilt the carb used a wrong gasket between the metering block and body and the thing was flooding the engine at lower rpms, also heavy black smoke until it would die. Could be a bad power valve also.

Numerous good items to check have been mentioned.  What hasn't been mentioned is the ignition coil...  Rare, but when they malfunction it's like throwing a kill switch in my experience.

Hope this helps!  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York