Doug Kraft

Trying to find a place to start looking. My Vette will run fine but on occasion will just quit. Lights work and there is no sputtering like it was running out of fuel, it just quits. It wont restart by popping the clutch but if I come to a complete stop it will start just fine. Msd distributor and 6al digital box new plugs and wires, charges fine has good throttle response from the Holley carb. Just need a place to start looking

san

Im assuming it is up to temp when it quits... I wouls suspect electrical, likely the msd ignition.

OldCarBum

If it's warmed up when it quits, try replacing the coil. A coil getting ready to go bad will shut down when warm and stop sending voltage to the distributor. After a few minutes it will restart and run fine.
Then next time it quits, quickly pop the hood and check if you have fuel to the carb. It could also be a bad fuel pump.

lionelhutz

A carb'd engine will generally sputter and die out if there is a fuel supply problem. On the other hand, an electrical failure that causes loss of spark will make the engine suddenly shut down.

Possibly some wiring that moves with the engine is making intermittent contact??

san

I would say coil as well, but intermittently I would suspect a bad connection somewhere to the MSD box, maybe the power lead for it is missing a beat or is in an overload condition, you could maybe try running with everything on,AC,LIGHT,BLOWER,HAZARDS...see if something trips it to quit, be sure to rev the throttle a bit and put car in gear when running some tests.

71VetteLover

If you're using the IGN terminal of your fuse block to power your MSD it's very possible your ignition switch is bad because it powers the IGN terminal when the key is turned ON. If your ignition switch is the original it's way past due for replacement anyway.

carriljc

I would suspect the coil also. I had a hell of a time with this ages ago. It would be running just fine and then just die. Of course, as soon as I opened the hood --the coil would start cooling down -- and then it would start again. I kept thinking it was fuel related.
I actually figured it out late one night when I had my timing light hooked up and the engine running... just sitting there spacing and holding the timing light blinking up against the wall.... timing light just going through it's routine blinking pattern....and I'm spacing.... and then it skips, and a slight miss. wtf? So, that makes me pay attention, and sure enough, it's actually missing... just barely noticable. So, I swap my coil out for the one in my old Datsun... and it runs steady.

If you don't have a spare coil, then I'd get generic replacement coil, and check this.