Eddie, can you clarify this:
but now starter will cut out right before it fires up any ideas?? im thinking maybe starter is going out but it cranks nice and strong.
If the starter engages and turns the engine well, than I guess it's fuel, as below. If the starter disengages early, then it's the starter, or associated wiring.
On Fuel Systems:
Ok, you turn the key to ON. The ECC turns on the fuel pump for about one second. You can often hear this in a quiet environment... just a quick whirr.
A good fuel system will, at that point, have the fuel rail pressurized to about 30PSI. If so, then turning the key to START should start the engine easily. The ECC senses the engine start and turns the fuel pump back on for the remainder of the drive.
Complicated? Yes. But, the idea is that you don't want the fuel pump to run continuously before the engine starts. Let's say you have a leaky fuel injector, or worse, a fuel leak of some kind at the engine. Or you just turn the key on to listen to the radio. This is Ford's failsafe for those situations. Many will simply bypass the whole deal and hotwire the pump to the ignition so ON directly powers the pump. It works, but has the associated hazards. They made it the way it is for a reason.
So, lets say you don't get to 30PSI in that one second when you go to ON? The injectors don't have enough pressure and you get a no start, and the ECC keeps the fuel pump off. I don't have a good measure, what is enough or not. Let's say 20PSI is marginal, just for talking about it.
Diagnostics... better to test before blindly buying and installing parts. The shop would hook up a pressure gauge to the fuel rail and perform the tests in the link at the bottom of my post.
Now, let's say you are broke, thrifty, etc... another thing you can do is to sit in the truck, turn the ignition ON (but not to START). You will get the whirr. Turn it back to OFF. Then ON, and then OFF again, maybe 5 times. Then start it. If it starts right up, you have a fuel starvation issue.
Fuel starvation can be a failing fuel pump relay, a failing fuel pump, of a clogged fuel filter. Could be the fuel pressure regulator, but that is rare.
If you get to this point, I would replace the relay. If it ends up not being the problem, then at least it is a cheap part and a good spare part to keep in the glove compartment, since all the relays are the same and it may help you later. IMHO, every explorer owner should have a $10 spare relay in the truck at all times.
Next is the fuel filter. If you have recently replaced it, well, an aside:
I had this same problem in another car. I was getting ready for winter, dumped seafoam in the tank for a preventative measure. From then on, if it was below freezing the car would not start. I replaced the fuel filter on a hunch(outside on a snowy day), and a bunch of purple crud came out of it. New filter, no issues. I guess the seafoam gelled with some water in my system?
There are plenty of diagnostics you could do at this point. Disconnect the output of the fuel filter and see if you get any volume of gas when you turn the key to ON. If not, disconnect the fuel inlet and try again. At that point, though, you might as well just replace the filter since you are there anyway.
Replacing the relay and filter as diagnostics are cheap and a good investment going forward.
Hopefully, you have it fixed by this step. If not, then you could test voltage at the pump for an electrical issue. Or, you could have a clogged filter sock and junk in the tank. Or, the pump could be going bad.
Remember, fuel supply is all about pressure AND volume. Well, that's a longer addition to a very long post.
If you have to get to the fuel pump, I highly advise the trick to remove the back seat and cut through the floor pan to get to it.
Also, just because it it my current pain: If you are in a northern state with salt, the ring that holds the pump into the tank may be corroded beyond use. I tried to re-use mine and now I have a fuel leak if my tank is full. That ring is stupid expensive, like over $20. I wish had replaced mine and make a better seal. What a lame way of sealing a hole. Grr.
If have read this far, than to be complete (completely long-winded, perhaps), a good fuel pump is capable of far more than 30PSI. Thus, there is a fuel pressure regulator used to bleed off excessive fuel back to the tank. That's why there are two lines at the tank. Let's say the pressure regulator fails open. Then, no pressure can build up. In the scheme of things a pressure regulator failure is rare, but worth mentioning.
A non-venting gas cap might possibly cause this. If you get sucking sound when you open the cap, that could be an issue. Easy to test, start the truck with the cap off.
Good Luck y'all.
