The easiest place to start is the ignition system. Since the engine has been running it would be good to confirm what the static timing is and that you are getting good spark on all four cylinders. Static timing can be set at 10 deg BTDC which should be good for starting. Check the operation of the vacuum retard servo on the distributor. Failure of the servo or a vacuum leak can cause high idle. What do the spark plugs look like? The condition of the insulator tips will give you a lot of clues as to what may or may not be happening.
As noted by craig300, if the fuel condition and condition of the tank are unknown I would be inclined to drain the tank and see what comes out. I will hazard the opinion that any 1800 that has sat unused for any significant period of time with the same fuel in the tank for that period of time will have issues. Most ‘ran when parked’ 1800s require a tank cleaning and sealing if they have been parked for any significant period of time.
Depending on the condition of the tank a 9 month old fuel filter may now be clogged. You can try a new fuel filter; but, if the tank is full of crap the new fuel filter may be clog quickly. Make sure that you have the correct large diameter metal fuel filter meant for the E engines. Be aware that the filter is on the discharge side of the pump and if the pump is original it is a rolling element positive displacement pump. Passing a lot of crud through the pump will shorten its life and its ability to generate flow. Hence the importance of making sure that fuel tank and the fuel is clean.
The acid test for fuel supply is delivered fuel pressure at the injector rail. This should be done on a running engine; but, since your engine does not run the ‘entry level’ requirement is that when you turn the key to the run position the fuel pressure rises to 28 – 30 psi. Fuel pressure is also a tuning factor in the operation of the D jet so the correct fuel pressure is critical for engine operation. If you cannot generate 28 – 30 psi of pressure then that problem needs to be addressed before moving on to anything else.
If the pressure rises to 28 – 30 psi; but, drops quickly you have a leak. This could be the pumps internal check valve or the fuel pressure regulator. These are annoying; but, not critical. You could also have a drooling injector(s). Carefully pull the injectors out of their holders with the rail attached set four cups under the tips of the injectors to catch any fuel. Turn the ignition key between run and off a couple of times which should run the fuel pump through its prime cycle. If any of the injectors leak then you have a choice of purchasing a replacement injector or sending the injectors out for service by somebody like RC Fuel Injection Services.
Pull the cold start injector from its mount on the manifold and make sure it is also no leaking.
If the fuel pressure is correct and the injectors do not leak then a basic flow test is in order. Get four pieces of clear vinyl tubing sized to fit over the tips of the injectors and about 8″ – 12″ long along with four small cups. Cups with measuring indications would be best. With the injectors pulled out of their holders shove one end of the tubing stubs over the injector tip and the other end into the cup to catch flow.
While having someone monitor the fuel accumulation in the cups so that you don’t get spillage crank the engine for 10 – 30 seconds so that you get measurable fuel delivery. They should all have equal delivery. Failure to deliver fuel on an injector indicates a dead injector or a wiring problem. Variation in fuel delivery indicates dirty injectors and a trip to the cleaners or replacement is in order.
Remove the cold start injector and place the tip in a cup to to confirm that it is delivering fuel during cranking.
The preceding are basics and once addressed should give you an engine that is able to run. It may run poorly; but, then you can get into the individual factors that may contribute to the poor operation.
Have you checked the valve clearances? Excessive valve clearance may be responsible for your high compression test on one cylinder. You may also have a worn cam lobe / lifter on that cylinder. Cam lobe / lifter wear is an exceedingly common problem on B20 engines with the original lifter design. However, this is normally not a problem that would cause a failure to start.