Truck Repair: Truck wont start, fuel line hose, compression stroke

Question
I have a truck and a few months ago i started it and drove it then when i parked the truck it would not start . Well i had a mechanic look at it and he said it was starter. So i went ahead and changed it and put new battery in becasue it was bad also. Well it took me a few months to get this sorted and when i go to start it isnt dead anymore but it wont start. WE checked for spark and pulled a plug out and put it to metal and had a spark. WE checked for fuel and poured starting fluid in carberator and still nothing. Someone told me to check the timing chain but im out of ideas. Can you help

Answer
The timing chain is obviously not broken, but there is a chance it has jumped time, and the chain and gears MIGHT be worn out.
Checking the timing is what is needed right now.
You need to make certain the timing mark is at or near TDC for cylinder #1, and also make certain the #1 cylinder is on the compression stroke, meaning both valves closed.
If you have it at TDC, stick some hose, like fuel line hose, into the spark plug hole, and blow on it. It should hold against you, and not allow you to blow through. If you can blow through, then one of the valves is open, meaning it may have jumped time, or you might just be on the wrong stroke.
Rotate the crankshaft one full turn, back to the mark, and try the hose again.
Once that is happening,(holding the air), and the timing mark on the damper is on, or slightly before TDC, remove the distributor cap, and make sure the rotor is pointing toward the #1 tower.

If it is pointing anywhere other than #1, it has probably jumped time.


And, by the way.....what year, model, and engine is it the next time.

Van