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caddmannq · 06-01-2003, 10:38 PM

Jonty, if you could see petrol squirting into the carburetor when you tweaked the accelerator puump, then the float boal wasn't dry. There was fuel in it. Now if at that time, after tweaking the accelerator & seeing the fuel squirt & cranking it, it didn't start, then the problem is electrical. An 80F day isn't enough to vapor lock any car I've ever seen.

However:

Ignition coils can fail in "fits and starts" if you know what I mean. It runs, it quits, it runs, it quits, it runs poorly, it finally dies.

Your car may have a bad ballast resistor. If it dies again, try jumping across it. It should run quite a while with a jumper on the ballast, but it's bad for the points. A bad ballast won't usually prevent it from starting, but it will die as soon as you release the key.

Ignition switches are prone to wear out, & that might cause the loss of primary voltage to the ignition coil. With the car running, try wriggling the key switch all about & see if it cuts out. You might consider taking a jumper with with you, so you can bypass it if the switch fails unexpectedly. That bypasses the ballast, BTW, so it's bad for the points too, but it will run like that quite a while.

Some cars don't have a fuse in the primary ignition circuit. A short circuit in the primary wire could be intermitant, somewhere between switch & ballast, ballast & coil, coil and starter, or coil and distributor. (The ballast or distributor itself could be shorting too.) Bumping the car uphill with the starter would torque the engine hard against the rubber mounts, and might have dislodged such a short. If a short develops, & the engine dies, putting a jumper to the coil won't work, as the circuit is still bled to ground somewhere. You should detatch the primary coil wire first. (Did you smell any wires burning?)

I had a car that died once just like that, and it turned out that some idiot (me) had dropped a small screw into the open distributor, where it rattled around until it eventually shorted the points to ground.

Finally, is the top of the coil clean? Dirty = bad.

06-01-2003, 10:38 PM	#22 (permalink)
caddmannq Registered User Join Date: Oct 2001 Location: Clovis, CA Posts: 2,481	Jonty, if you could see petrol squirting into the carburetor when you tweaked the accelerator puump, then the float boal wasn't dry. There was fuel in it. Now if at that time, after tweaking the accelerator & seeing the fuel squirt & cranking it, it didn't start, then the problem is electrical. An 80F day isn't enough to vapor lock any car I've ever seen. However: Ignition coils can fail in "fits and starts" if you know what I mean. It runs, it quits, it runs, it quits, it runs poorly, it finally dies. Your car may have a bad ballast resistor. If it dies again, try jumping across it. It should run quite a while with a jumper on the ballast, but it's bad for the points. A bad ballast won't usually prevent it from starting, but it will die as soon as you release the key. Ignition switches are prone to wear out, & that might cause the loss of primary voltage to the ignition coil. With the car running, try wriggling the key switch all about & see if it cuts out. You might consider taking a jumper with with you, so you can bypass it if the switch fails unexpectedly. That bypasses the ballast, BTW, so it's bad for the points too, but it will run like that quite a while. Some cars don't have a fuse in the primary ignition circuit. A short circuit in the primary wire could be intermitant, somewhere between switch & ballast, ballast & coil, coil and starter, or coil and distributor. (The ballast or distributor itself could be shorting too.) Bumping the car uphill with the starter would torque the engine hard against the rubber mounts, and might have dislodged such a short. If a short develops, & the engine dies, putting a jumper to the coil won't work, as the circuit is still bled to ground somewhere. You should detatch the primary coil wire first. (Did you smell any wires burning?) I had a car that died once just like that, and it turned out that some idiot (me) had dropped a small screw into the open distributor, where it rattled around until it eventually shorted the points to ground. Finally, is the top of the coil clean? Dirty = bad. Last edited by caddmannq; 06-01-2003 at 10:42 PM.