I wouldn't go back to that repair shop, Do It Yourselfers might swap out sensors to "figure it out" but Pro's wouldn't/shouldn't, they are too easy to test.
Computer control doesn't change how an engine works, it makes it more reliable but the basics are still the basics, just rely on your past experience.
Spray some gas or starting fluid into the intake, crank it and see if engine starts,
If it fires up then dies the fuel system is the issue.
If it doesn't fire up then spark is the issue.
'94 4.0l uses an EDIS-6 module to run the spark, on my '94 the EDIS module is on the Front Side of the rad support, by the battery, have to get under truck and look up to see it, but they hardly ever fail except in front end collisions :)
The EDIS module gets a #1 TDC pulse signal from the CKP(crank position) sensor, located near the crank pulley, it "reads" a tone wheel, looks like a gear, on the back side of the pulley.
So this works like a distributor and points but without the extra moving parts(pulley was already a moving part, lol)
EDIS module hooks up to the Coil Pack, 3 coils in one package, each coil sparks 2 spark plugs at the same time, Ford calls this a Waste Spark system because one spark happens in a cylinder on the exhaust stroke so it is "wasted".
These coils work the same as all automotive coils, you power primary up with 12volts, then cut the Ground to get the secondary to spark.
So easy to test each of the 3 coils that way or use OHM meter, they test the same as single coils.
So that is the spark system.
When key is turned on the Coil Pack and EDIS module get 12volts from the EEC Relay, so does fuel pump relay so if thats working then EEC relay is not the issue.
Test that coils is getting 12v, there are 4 wires at coil connector, 3 are "grounds" from EDIS module, the 4th is the 12volts
When you crank the engine the CKP sensor sends a pulse to EDIS module which then grounds and ungrounds each coil to spark them in time with #1 TDC and firing order on coil pack.
EDIS module does pass on the #1 TDC timing to computer so it can time the fuel injectors, and the computer does send back advance and retard spark timing based on drivers foot on the gas pedal(TPS) and engine load, but EDIS module doesn't "need" the computer, to spark engine at the correct time.
If there is no CKP sensor pulse then there would be no spark or fuel injection.
You can try this, pull out an easy to get at spark plug.
Clean it so it is dry
Put it back in the engine
Crank engine, don't touch gas pedal
Pull out spark plug, if it is wet with fuel then CKP sensor is working
Good read here on Ford EDIS: Ford EDIS technical information
It may "seem" complicated but so were distributors, points and coil until you learned about them.