It was running and it made a backfire and since then it cranks but won't turn over and start what could be the problem

That could be a timing issues when it back fires
Why ,no idea,not a question you can guess at as we do here
Could also be a vacuum leak & lean fuel mix
When you say cranks the motor turns over nothing else
Cranking has nothing to do with the motor starting or running
You have a no start & back fire as I gather

it flooded. step on the gas pedal fully and crank the engine; that forces it to go into a clear flood mode by turning off the injectors. it may take a little while, but it will start.

Old post but , this answer covers all , of this type symptoms.
new head,
ran for 30 minutes
so does it crank ? ok? if not dont crank, it can start.
so crank is next. (first)
backfiring (true to the air cleaner) usually means TIMING IS way off and sure engines can start with timing way off and then stall and flood out.
nothing new there.
you did not time the engine correctly.

get the FSM on engine. read the pages.
or go to alldata.com and read that.
for others searching using google, my lil. contribution;

Have you checked Google I found this hopefully it's not your timing or it may be flooded but doubtful have you tried spraying starting fluid into the intake while cranking it

Most Fords have a fuel reset button. When you ran out of gas you tripped the circuit. Most of the time the button will be on the passenger side by the kick panel. The exact location should be in your owners manual or your local library or auto parts store will have a copy of one for your specific vehicle.

Sounds like the timing is to far advanced.****** the timing until motor turns freely when cranking it over.

Well, since it won't run, you cant check timing with a light. You could try static timing: Bring #1 piston to TDC by mark on scale by crank pulley. Take upper timing chain cover off. Cam pulley should have a mark or circle or dot that lines up with mark on bloick. (Need to make sure you are on compression stroke, not exhaust stroke of piston. How? Best way is pull spark plug and hold finger or thumb over plug hole. As you turn crank (clockwise) with a socket approaching the TDC mark, you will feel pressure build on your finger if you are on compression stroke. Could also have someone bump starter a little at a time, you can feel pressure build on your finger as piston approaches TDC. When it's close, use socket to line up crank pulley with mark.) Now check cam pulley for those timing marks. Valve timing off is often cause of backfires. So is too much gas, but first I would make sure timing is right.

dose it backfire when you crank it over. if it dose your timing is off. If it dosent backfire when you crank it then look at all your wires and make shur you pulged ever thing in. and if you have one ground not hooked up that can cause a no start do you have fuel?
let me know and we will help more if needed

stockam auto

If you need further help, reach me via phone at https://www.6ya.com/expert/dennis_f849d3d6a68c6430

your camshaft is a half round out. turn the crank till it is at top dead center then take your chain off and turn the camshaft a half roud to line up with crank. then put back together and start

I still think this is a timing problem, most likely with the crankshaft sensor. However, it could also be in the throttle positioning sensor, since you had raised the idle to get it to work momentarily. Also, the mass air flow sensor cannot be ruled out entirely. I would start with the crank sensor, then the throttle positioning sensor. Try these and let me know.