55 vickey, 272, holley on a 57 intake, Pertronix in a 58 distributor. Car was running sweet, all of a sudden it dies when I take my foot off the gas or even back off, seems fine on the highway, just can't slow down. HELP, Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Gary your chance of getting a right answer to whatever problem is directly linked to how well you describe what the problem is, when it occurs, and a LOT MORE INFORMATION from you. If you need help then please YOU DO MORE WORK. For all anyone can tell it might be death rays from MARS.

Ok Pete, point well taken. I drove the car to a car show Saturday, it ran fantastic. After the show I was leaving the parking lot when it hesitated, I stepped on the gas and off I went. When I backed off on the throttle for a curve, the engine died, I immediately floored it, it fired back up and kept running, as long as I had my foot in the carb, riding thru town was a nightmare, left foot on the break and right on the gas, or throw it into neutral (auto). I checked all the plugs today, they all look great, it's getting plenty of gas. As I was going 55 or 60 you could feel the engine surging. I'm thinking carb cuz of the reaction when I open the throttle plate. I took the distributor apart today, everything is working great. My next adventure will be to put the points back in and see what happens, or am I heading in the wrong direction. The car will not idle at all, the throttle plate has to be open for it to run at all. Hope this helps a little, thanx, Gary 

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Gary:

A few things come to mind at this point.  One, the secondary throttle plates are standing slightly open, essentially a huge vacuum leak that the idle circuit can't overcome.  If it did, the idle speed would be way too high.  Another thing could be clogged idle circuits.  Also, a broken lead in the distributor that intermittently makes and breaks as the vacuum advance moves the point plate back and forth.  Good luck.

John

John - "The Hoosier Hurricane"

You didn’t say which Holley but I’m assuming a four barrel.  Add to the list of items to check: the gasket between the throttle plate and the main body as any air sucking in at that point will disprupt idle circuitry flow.  Same goes for a ’57 and up Holley two barrel.

Lorena, Texas (South of Waco)

i'd bet on a vacuum leak too.

check vac advance from carb to dist. also.

pcv system?

gasket at base of intake and carb.

rubber vac plug cracked on carb vac outlet?




This ain't no L-Kamino!

I did a complete vacuum check, everything checked out fine, finally I unhooked the vac advance, started it up and it's as sweet as ever. I think I had to do this in the spring also, sometimes the senior moments come in to fast. I checked the unit and if I apply a vacuum it moves the plate. For now I'll drive with just the mechanical until I can get a new unit. Thanx for all the help. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Sounds as though you have too much initial advance, and/or need to hook the Distributor veccum line to "ported" source on the carburettor. That would be a vacuum source that is above the butterflies and not functional at idle. That way you'd still have the vacuum at cruise. I'd also recommend you recheck you timing with the vacuum line removed, it may have been set incorrectly with the dist vacuum still attached. Don't be surprised if the idle speed has to be reset after all this.

Frank/Rebop

Bristol, In ( by Elkhart) 

The car started acting up again yesterday, I took out the pertronix, put the points back in and its fine. I was timed in the upper teens with the pertronix in it and 15 vaccuum, now the timing is back to 8>9 and almost 18 on vaccuum. Got a little stumble off the line but I'll work that out. I've got the vaccuum advance hooked back up also, seems to be working fine.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Just curious as to whether your vacuum line for the distributor is hooked up to ported or direct vacuum? You may have said at which case I just overlooked it.  If hooked to the intake, the vacuum source will be direct vacuum but if hooked up on the carburetor, it could be either depending upon the port being used.

Lorena, Texas (South of Waco)