Will Not fire-

Have you checked the vacuum pipe from the distributor to the carburetor, its the automatic advance, if this is leaking then that will cause a sudden failure when extra gas is applied .

Check inside the distributor cap for cracks ect.

replace the ignition module or pickup coil located under the distributor cap ignition modules work when cold and will stop firing when they are warm when they r going bad

Even with a new distributor cap you need to check for spark. Is there spark to the plugs? If you are getting fire, compression and fuel at the correct time - you should be starting. Did it stop running suddenly? Have you eliminated the timing belt? Does it turn over normally or faster than usual? Does it sound like it wants to start - if so it could be a restricted fuel supply.

1 Inspect Distributor Cap Loose, Cracked or Worn Distributor Cap. 2 I 1 Inspect EGR Valve Improperly Functioning or Faulty EGR Valve. nspect

1 Inspect Idle Stop Solenoid Damaged, Loose, or Faulty Idle Stop Solenoid
Distributor Cap and Rotor Kit Loose, Cracked or Worn Distributor Cap.

Check the ignition switch located under the dash on the steering column. Check to see if you hear an electric switch go on when you first turn the key on.

Check for possible vacuum leak, maybe a hose off or partially broken. Make sure your firing order is correct when reconnecting those wires to the new cap.

You must have the plug leads in the wrong place on the distributor.
Firing order is 1-3-4-2
Remove the distributor cap. There is a tiny mark on the aluminum body where the cap sits on it. Turn the motor clockwise by hand until the rotor lines up with this mark. #1 plug lead should be in the distributor cap hole closest to the rotor in a clockwise direction.
If the motor still does not start rotate all the plug leads 180 Deg.

Sounds like you have the firing order right but your off on the #1 on the distributer. Every time you get an explosion coming from the carb its misfiring. Find the #1 on dist and continue with firing order

it might be the optispark harness wire.it starts and runs good. once u turn it off its hard to turn back on?