Very interesting about WD40 that it will run on it. I am sure it must be the propellant that helped more and not the solvent, by itself, that WD40 truly is.

I presume this is a K-JET system. In this case, it runs on having the proper fuel pressure going to the right places.

Since it does run, somewhat, we can rule ignition woes for the most part.

Timing of the valves and the distributor would be my next highest priority.

Check for All of the marks to be smacking on their respective marks.

If you roll up on number one's TDC make sure the front two lobes are laid out like cats ears by looking through the oil filler cap hole.
Check to see if the distributor rotor button is pointing at number one wire. I think there is a notch that is in the body of the distributor, which is under number one wire too, but I could be wrong on that detail. Double check firing order and clockwise too!

Ok, that takes care of half of the mechanical things. Half, meaning the fuel system on this car is also mechanical. You should have proper spark timing and compression if the others are set.

Hard starting?
Next are we getting fuel? If so, how are the plugs burning any of it? Are they wet or dry after a cranking session?
Any one wet or all? Leaky injector, maybe? If all are wet it means you have enough pressure to open them at least!
All dry means you do not? But pumps can run but is anything flowing? If they flow then why not enough pressure? Could be bad check valves or a run away control pressure regulator dumping it.

HARD STARTING?
In most cases, I have seen bad tank pumps, bad check valves on the main pump outlet or the main pump has a problem getting fed or keeping the line full. Take your pick on which side effects what.

This is where you loosen lines and trace flows and squirts or you get a pressure gauge with fittings to see what the control pressure regulator is doing in between the pumps and the fuel distributor which ultimately lead to those injectors. They have to have 35 psi to push open the nozzles to even fire.

This is a continuous injection system. Mixture is set by the air flap while working with or against the control pressure. The frequency valve that buzzes is also a mixture control that works sort of concert with any O2 sensor equipped car via the ECU. IF IT HAS LAMBDA SOND.

If your car does not, does it have an EGR. That could be stuck open and cause an air leak issue or lean problem that could come and go.

We need to know more about the car in any case. The pressure gauge thing will be involved eventually unless others lead you to a specific component with trial and error logic!

Glad to see you reported your problem away from the LH systems.
The thread heading will bring others to play in your ball-field!
Lucid is real sharp on this stuff. Look for his advice on his past posts if he does not throw his hat out on the mound!
Phil