Engine shutdown dilemma
 

On to the next dilemma.....was driving my 80Z project the other day, when the engine began surging (knocking off, then firing up for a few seconds, then shuttign down again). I thought maybe the gas gauge was broken, and I ran out of gas. The car completely shut down, and could not be started....about 60 seconds later...it fired right back up.... drove for another half mile or so, and the same thing happened. Each time if I wait a minute or so, it starts right back up.

It has happened again, but usually not until I drive for 10-15 mintues or so, when the car warms up, and I'm not out of gas....... what can I check?

sounds like carb float is sticking.

Or the coil is going bad. They sometimes quit as the coil warms up, and once the coil cools a little it works again. Next time it does it pull a plug wire and check for spark. If there's nothing it's probably the coil.
Check the fuel filter too, and don't forget the one that's in the inlet of the carb hidden behind the fitting.

Could also be your mechanical fuel pump giving out under the heat, had that before. Next time it quits, pop off the air cleaner lid, give the throttle some pumps by hand, and look to see if gas is squirting down inside the carb.

Oh yea...one other thing....it will run all day in the driveway. I have had it running for half an hour in the garage....different throttle levels, everything is fine

Well that certainly throws another variable into the mix! If it wont do it sitting, then there's a chance it's a fuel issue where it's picking up junk in the tank, or bad fuel. Also possible there's an intermittent short in the ignition system that only opens or shorts when it's moved when driving.

This car has been sitting for about 18 years. I'm going to work through replacing most of the engine components....think I'll start with coil, fuel pump, fuel filter, and see what happens...what fun!

If it's been sitting that long you need to pull the gas tank and make sure it's clean inide. You alo need to either replace the fuel lines or make sure you clean them inside. When gas dries inide a tank sitting that long it makes an ugly powder residue that will get picked up as the new gas washes around in the tank.

wow after 18 years its pretty easy to say u probably need a new tank or atleast have it cleaned and sealed again.u can also have them boiled if there not to bad but not sure what they charge might be better to just buy a new tank probably cheaper that way.

X2 on BB427. They make some pretty good tank cleaners out there or at least used to. I used one on a Harley that I re did years ago, and it worked very well.