1992 Ford Explorer won't start

On a cold day last week, my explorer sport hesitated a little when starting. The next morning, it would not start at all. The engine cranks, but does not turn over. So far, all the fuses appear to be fine; the fuel pump is pumping fuel up to the fuel line (i disconected the hose at the injectors); the spark plug wire i checked had spark. From what I understand, the timing is a chain, not belt. Is it possible the timing is still off? Is there a sensor that I need to check?

You mean the engine cranks but does not fire (start). If it cranks it is turning over. If you have fuel and spark, then you could have an overly lean or rich mixture causing the engine not to start. One thing would be the engine coolant sensor that tells the computer the engine temp. If it thinks it 90 degrees out and its 20, you could get a no start or extended crank. Also the air temp sensor same way. Or you could have an over supply of air caused by a stuck or malfunctioning idle air control, or air leak, etc. Also spose the egr could be a factor if it were stuck open. If it were a crank or cam sensor, you wouldn’t get a spark I don’t think. Don’t know how you would check these without getting a computer scanner on to see what the sensors are doing etc. Also, you could peer down the oil fill opening as the engine is being cranked to make sure the lifters are moving in case the timing chain broke. Maybe a little starter fluid would tell you if you’ve got a mixture issue.