Maybe a dumb question and I may have my own solution but here goes.

I just got my dizzy rebuilt for the coupe which has electronic ignition. I went to reinstall and set the timing marks to TDC on cyl 1.
Isn't there two TDC's ? ... one for compression and another for exhaust? So I took the oil filler cap off and worked out that the TDC with the first valve down was probably the exhaust stroke and the next rotation would be the TDC I need.

But it still will not start and backfires
Any thoughts?

Take off the dizzy cap when you turn the engine to tdc (by hand)rotor button should be pointing to number 1 plug or #1 lead on dizzy cap from memory. Possibly 180 degrees out.
Also are your leads in the correct direction and firing order ? 1,3,4,2

If you remove the #1 spark plug (the front one!) and put your thumb over the hole you can feel the pressure when its on the compression stroke as it approaches 0 degrees. Be turning the pulley clockwise. Try and advance it a bit say 5 degrees before TDC and set the dizzy up so the rotor lines up with the #1 lead. Start the car and then set the timing from there.

As Datsandy says check the firing order 1342 and remember that's in the counterclockwise direction.

Thanks guys. Both confirmed my assumption of the second time that the crank rotates number 1 piston up and the valves are both closed that this is the right stroke. Then i should insert the dizzy so that the rotor points to number 1 plug lead. Yes I have the right order of 1342 anticlockwise

Will play again on the weekend