Check your vacuum diaphragm for leaks or cracks when you have a chance.

Frank/Rebop

Bristol, In ( by Elkhart) 

Just got back from a nice ride. Running great, the only issue was a little hesitation on passing and a little stumble on a quick takeoff. Starting better than ever. I checked the vac with a different guage, it read a little over 17. I'm gonna check it with another one this afternoon, ones gotta be whacky. I also found the cigarette lighter stuck in......don't see a correlation, but it's fixed now. Before I put it away for the winter I'm gonna put the Pertronix back in and see what happens. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

The vac was at 20 btdc with the pertronix in it and it ran great, when I took the pertronix out it wouldn't start until I took it to 12 btdc, at which point it ran the best at idle and had the highest manifold vac. The car is in park when I take all my readings. As I said in my second post, it ran great until I left the car show, every time I took my foot off the gas it died, put my foot in the carb it fired back up but ran like hell. Couldn't get it to run until I unhooked the vac advance, plugged it off and it was ok, for a couple miles, then bad again. This is when I took the pertronix out. The vac advance was hooked up to manifold vac, now it's at ported vac. The car ran great with the pertronix in it, what happened to make it go bad I don't know but right now it's running and sounding good with the points in it and less timing. I'm gonna put a new coil in it and check out all the elecrical. I had the distributor out, all advance move good and all electrical connections are good. Finally got a good day so it'll go for a nice long ride today so I can see whats going on now under driving conditions. The specifics with the power valve I'm not sure, but like I said, it ran good for a long time, just all of a sudden it went bad. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Gary,

           Really difficult to diagnose from words, but I'm begining to smell an electrical issue here. Check, double check and then recheck all the ignition stuff try another coil, make sure nothings loose, or grounding or separating inside the insulation. Quite honestly,most carburettor issue turn out to be electrical.

Frank/Rebop

Bristol, In ( by Elkhart) 

Gary at this point I know you are sick and tired of all these questions that you feel you have already answered. But what you KNOW and what we (I) KNOW may not be the same. You say car has 15 inches of vacuum at idle. Is this MANIFOLD VACUUM in gear or in neutral? Important difference, since with a R/V cam I would expect at least 18-20 inches. When you say the engine needed 20 timing with the Pertronix and 12 with the factory points WHAT does that mean? Is this BTDC? To get the best idle, the highest manifold vacuum, the best drivability, or something else? Did you call the Tech Support at Pertronix and ask their advice? I have a Pertronix that I have had for almost 10 years and if it died I would not go back to points. Your 4BBL holley is really a TWO BBL until you develop enough manifold vaccum to open the secondaries and if the carb is new what power valve is in it? Like I tried to say the better you define what is going on the more likely you will get an answer that solves the problem.

Not sure about the cam specs, I'll have to check with engine builder. I do know that it was degreed in. The guy builds racing motors and I pit for him on the circuit for enough years to know his quality of work and success with his engines is not an issue. The vac at idle is a steady 15, it goes up when I rev it. When I rev it in idle it revs very fast and smooth, just under load on acceleration is the stumble.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

As Pete suggests, cam is likely not the problem but does need to be ruled out so here are more questions.  What’s the specs on the camshaft?  Was it degreed in or just installed counting the links in the chain?  And if degreed in, was more than one cylinder checked?  How’s the manifold vacuum at idle?

 

But back to the sluggishness.  The distributor could potentially benefit from some lighter springs so that the advance comes in earlier.  Especially if your distributor originally came out of a pickup or truck.

Lorena, Texas (South of Waco)

I've got 3 ground points to the frame (old stock car days), the braided wire in the distributor is connected, I'm very confident in my electrical system. I think it's primarily just tweaking. With the points back in I feel like I have a viable starting point, accentuate the positive, eliminate the negative. O my O my, what will happen once the quads or deuces go on...........ain't gray yet.....but I can see it coming.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

With the Pertronix system, the little brain chip sets the "dwell" time to charge the coil - with your points, the point gap does. For those with a "Dwell/Tachometer" - you can hook it up to the negative side of the coil and read the difference. How long you let the coil "charge up" has everything to do with how hot the spark is. Old dual point systems run the dwell out to get better (longer) charge time - hotter spark. The Pertronix dwell is pretty much a fixed value based on how much current it can handle at idle.

The Pertronix instructions don't warn you to be sure the swivelling point plate you attached the unit to is securely grounded. The point systems have a little braided ground wire that grounds the moveable portion of the point plate to the fixed portion (that hopefully then carries the ground to the engine block). Did you retain the braided jumper when you fitted the Pertronix module? To get the greatest possible spark out of the coil, you want it running on the greatest voltage your "switch" (points or Pertronix) will tolerate and grounding to the best (lowest) ground you can find.

 
 Steve Metzger       Tucson, Arizona

I replaced a 1 month old coil at Columbus! It can happen! Chuck in NH

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