Ok here is the deal 94 4.0 have to use starting fluid to start after that will fire up on its own most of the day.
fuel pressure check is good, when key is turned on primer pump runs and won't shut off. Can't tell if keeps running when started also changed fuel filter under driver side.
is there a filter I could be missing?

 

Starting fluid is ether, it has a much lower ignition temperature than gasoline, which makes it a good starting fluid, lol, for gas or diesel engines

Couple of things
The reason a gas engine needs compression above 8.0:1 is because gasoline spray won't ignite with a spark, only gasoline vapor can be ignited by a spark so the gasoline must be heated up enough to get minimum 30% vapor in the cylinder.
That's why all cold engines need to be choked
In cold temps gasoline spray is only about 10% vapor, so you add 3 times as much to get the 30%
Once engine fires up cylinder get hot pretty fast, so pre-heated, and more gasoline vapor.

Fuel injection computers have a Choke mode.
Computer has its own coolant temp sensor, ECT sensor, that tells it when to choke the engine for cold start.
Choke Mode is high idle, Rich fuel mix and advanced spark timing(same as choke plate did on carb engine)
When you start engine with ether does idle go up to 1,100+ and stay there until engine warms up, and idle is 650-700?
If not then replace ECT sensor, NOT ECT SENDER, sender is for dash board temp gauge, no connection to no start or computer.

Running fuel pressure in 1994 should be 30-40psi
Key off pressure should stay ABOVE 20psi, for many MONTHS, not minutes, hours or days, MONTHS!

If you are losing pressure key off then there are 3 places to look, assuming you don't smell gasoline from broken fuel line.
1. Check valve inside fuel pump
2. Valve inside Fuel Pressure Regulator(FPR), on engine
3. Leaking injector

#3 is unlikely because you would report God Awful MPG and grey/black smoke on startup


Fuel pump should only run for 2 seconds with key on.
If it stays running then someone may have "jumped" the Fuel Pump relays ground

Look here: Ford Ranger - Testing EEC-IV Equipped Engines

Find your OBD connector in engine bay, should be between fuse box and firewall on drivers side, may have a cap on it
In diagram above Fuel Pump slot is IDed, if you put a jumper wire in that slot and Ground it Fuel Pump will run full time when key is on.
Doesn't hurt anything
Fuel pump is on all the time when engine RPMs are above 400, so all the time while driving

 

thanks for the info makes a lot of sense will start there

 

Ok now I have another issue my son decided to attempt a cold codes test with jumper on eec. He turned the key to all the way heard a pop now nothing.