I need a diagnosis

[dlrshort]

Today I took my '66 roadster (L-71) on a 50 mile trip (100 miles round trip). On the way, only about a mile from my destination, the car stalled out almost like when you turn the ignition off; that is, no sputtering or strange noises. This happened at a stop light. I cranked it over 2 or 3 times and it started up fine and ran perfectly. Then on my return trip at about 60 mph the same thing happened. I coasted and pulled over to the side of ther road and the car started again after it sat a moment and ran flawlessley the rest of the way home. I have a correct, recently rebuilt 3367 Holley carb. on the car. The car has been running fine except that the choke has been a little erratic. That is, it doesn't always go down to the low end idle after it has been running a long time. Or if it does it may jump back in to a higher RPM. I don't smell any gas. No back firing is occurring. Any ideas whether I am dealing with a carburetor issue or an ignition issue? Any help would be greatly appreciated.

 

[Grizzly]

Random Shut down

Had a Jeep do that. Broken wire in the coil. Cranking it must have kind of weld it back together. Vibration shook it loose.

 

[studiog]

My 2 cents... My best guess would be that it is an ignition problem based on your description of how it just dies out as if it had been shut off, no sputtering, hesitation or backfiring. I would start by checking out the ignition system. Good luck.

 

[dlrshort]

The concensus is that it is probably electrical or possibly a coil problem.
Two ?s: 1. Is it also likely that it is a fuel pump problem? and 2. Is it worth just replacing the coil? Since it is an intermittent problem, I'm not sure how to approach it.

 

[attret00]

Had the same identical problem. It is the coil. There will shortly come a time that after it cools down it won't start again and your'e stranded. (experience talking)

 

[Neal]

I had that happen on the first car I ever owned, a '67 Impala SS 396. The problem was electrical. One of the wires from my coil was hanging loose and would occasionally ground out against the exhaust manifold. Stopping (after it died) would cause it to move and/or rotate the exposed section of the wire from the manifold. A buddy's dad, who was one of those old time mechanics that would listen to the tappets with a broom handle, figured it out!

 

[magicv8]

It's electrical and it could be anywhere. Try this sequence:

Disconnect and clean the two body plugs in back of the fuse box.
Loose wires at coil primary or secondary.
Loose wire at drop resistor.
Key switch.
Broken ground wire to vac advance screw inside distributor.
Condenser if you have points.

 

[dlrshort]

Back again, I removed the shielding and lifted the coil out and I see a broken wire on the (-) side. The 2 red wires are intact as is one of the black wires which runs down through the engine compartment. Is this a ground? If so, where does it ground to?


Thanks

 

[JohnZ]

There's only one wire on the (-) terminal - that's the small black primary wire to the points in the distributor; if it's broken, you'll have no spark. The (+) terminal will have the two pink wires, and a black wire from the radio noise suppression capacitor mounted next to the coil (if you have a radio).

 

[dlrshort]

There's only one wire on the (-) terminal - that's the small black primary wire to the points in the distributor; if it's broken, you'll have no spark. The (+) terminal will have the two pink wires, and a black wire from the radio noise suppression capacitor mounted next to the coil (if you have a radio).

John, this broken wire obviously came from the noise suppression capacitor, but it was attached to the (-) terminal. Would that have caused a problem? My symptoms were engine cutting out randomly. I think when the wire came disconnected from the top of th capacitor that it may have been shorting out against the mounting bracket.

 

[JohnZ]

If the broken capacitor wire was connected to the (-) terminal and was touching the bracket, it was grounding the distributor primary circuit, which essentially closed the points every time it touched the bracket - would definitely screw up the spark. Could have been worse if it had been connected correctly to the (+) terminal - that would have dead-shorted the ignition feed to the coil.