Walk through this.
Before you do, make sure you have 12vdc to the coil at start.
a few things I would try based upon your condition,
Check all the rubber vacuum lines and especially the large rubber intake boot for cracks.
Ljet requires no leaks at all in order to start. The vacuum of the engine opens the flapper door in the AFM to get the pump working and if you have even a minor leak of outside air, the door won't open, you get no fuel, and the car won't start.
To verify this, you can remove the a
Large AFM rubber intake hose at the AFM and stick a pencil in the AFM to hold open the units flapper door which will turn on the fuel pump. If you do this with the key on, you will hear the fuel pump start.
If you do it for a while , you WILL hear the fuel pump change tone as the fuel pressure gets up to normal pressure.....if you don't hear that tone change, you have a fuel delivery problem, leak, blockage, out of fuel etc...
The pump will change tone from a higher pitch free running pump to a lower pitch sound once it hits normal pressure....then the pump is working harder. It's fairly easy to hear.
Vacuum lines, intake boot, injector seals, intake runners, gaskets and hoses...., valve adjustment, valve cover gaskets, head vents if you have them, oil filler cover gasket and o-ring in cap.All of that can and does add unwanted air to the system that will make starting damn near impossible, and super hard to tune up.
Fix all the air leaks and old hoses.
L-jet is a rock solid system with many cars still using a modified version of that system even today.
Two ways to measure air, with air flow or air pressure.
L-jet is air flow and it is not only simple, it's super reliable once you fix the air leaks with new rubber hoses.
You mention the car has been sitting for a while, well rubber wears out and cracks....so fix and replace what it bad.
You can replace everything with new EXCEPT the large rubber intake hose...that is NLA,
So be gentle with it, and remove it to look at it, the crack will be underneath at the turn in the hose in a place you cannot see with the hose in the car. some rubber goo, cement, tape , caulking all wil do the trick to seal up the hose while you look for a replacement.
http://manuals.type4.org/ljet/