I have a '94 ranger xlt ext cab 4.0 4x4 with 88000 miles on this motor. There are times that it will just not fire. It cranks until the battery is dead but will not fire. Some days I can go out and it starts with no problem. Runs rough then idles up and smooths out after about a minute. I get gas and spark all the time. Any ideas would help. Thanks,

 

Welcome to the forum

The 3 things a gasoline engine needs to start are
spark, at the right time
fuel, mixed with air
compression

Not a compression issue as that is never intermittent, its mechanical so doesn't "self repair", lol

So you are not getting fuel or spark or both if engine doesn't start, this is 100% not a guess
You can do 50/50 test
Spray fuel into the engine manually
Try to start
If it fires and then dies you have spark that's timed correctly but no fuel from injectors
If it doesn't fire then you have no spark
50/50 instant results

Spark testers don't work and fuel pressure doesn't mean fuel IN the engine

There is a CEL(check engine light) on the dash/cluster
It should come on with Key ON, this means Computer is powered up, no CEL = No Computer, so no start
When you crank the engine over with starter motor the CEL should go OFF, this means Computer is getting a timing pulse for injectors, no pulse = no injectors

When you first turn on the key, and CEL comes on, you should hear a HUMMMM from behind the cab, thats the fuel pump, it ONLY comes on for 2 seconds, but its not quiet
Cycle key on and off as much as you want so you HEAR it, and then know what to listen for when there is a No Start

1994 Computer
I had to replace my 1994 4.0l computer's 3 capacitors a few years ago because of intermittent No Start and running issues
Not hard to do and under $5 for new Caps

These 3 capacitors last about 20 years, mine were pushing 26 years, yours are 28 years old

Look here: Ford EEC-IV
Picture of Fords EEC-IV computer
You can see the 3 BLUE capacitors that need to be changed
They can be at different places but there will be 3, and all 3 need to be changed
One of them effects fuel pump circuit, for sure
Take pictures before removing caps as they have a + and - side, and a uF designation which needs to be matched exactly
Each also has a voltage, like 16v or 50v, you can use a higher rated voltage but not lower
So if a cap has 16uF and 30v, you can used a 16uF and 100v

 

Thank you. Where can I buy those capacitors? the CEL works as you said. I hear fuel pump every time the ignition is turned on.

 

Google: electronic components (name of your town)

These places sell capacitors and resistors, all sorts of circuit board parts
Usually have to buy them in 3 to 5 of each value in a pack, but they are cheap

I do see where people are selling Ford "capacitor repair kits" on line, make sure it comes with 5 or 6 capacitors as Ford used different uF values over the years
But $15...................caps cost maybe 50 cents each usually 30cents each

 

How was it you knew to replace the capacitors?

 

Over 20 years old would be the first thing, lol
But one of mine was visually leaking, easy to spot
But when changing all 3 a second one was also corroded on the bottom and wire lead was barely attached

This is a Ford EEC with caps being replaced: Capacitor Repair: Ford A9L ECM « Moates Support

Has pictures of damaged caps
Caps are in different places in each year, and there can be 2 or 3, but easy to see them

There is a + and - side, and each cap can have a different uF value and Voltage, take lots of pictures

Replacement uF must match exactly, replacement voltage can be higher but NOT lower
i.e. 16uF 30v can be replaced with 16uF 100v, but not 16uF 16v