My engine wont start for days, then starts?

Having close to same problem but it starts randomly or was but hasn't started now in a week. We replaced the battery, ICM, spark plugs & wires. I'm tryin to think of what else was replaced but will the coolant temp sensor cause it not to start after a while of using it. We r getting spark or whatever to 1st spark plugs and but the next 3 he chkd we're not. I'm tryin to get someone to come get me so we can go get parts needed but thought I'd ask on here 1st so maybe if it's something we haven't thought of I can get that too when I go. Pls help we gotta get vehicle running & get BK to work plus need it bc I take care of my grandma.

The fuel pump is working & he's getting fuel to spark plugs. I'm kinda guessing it may be crankshaft position sensor.