I could use some advice. My Ranger normally runs great -- a 98 4.0 OHV with 175,000 miles.

In July I replaced my fuel pump and fuel filter after my stock pump died. Everything was fine for a few weeks, but every now and then the motor would crank but not start. It would do this at completely random times. Got a new battery because it was time for a new one anyway. That did not help the issue at all. The issue started to get more and more frequent until one day last month, it refused to start at all and left me stranded at work. Towed it home. I did a spark test and got no spark.

So I changed the spark plugs, wires, and coil pack. (it was due for new plugs anyway). Right after doing that, it started-----ONE TIME. The next day it was back to not starting. Tried to start it every day for 2 weeks after that, and it would not start, even though the battery was charged.

Then I got a new fuel pump relay. It fired up IMMEDIATELY after changing that relay, and I drove the truck for a week. Everything was fine. It started strong every time I started it. Thought I found the problem.

Then 2 days ago it wouldn't start again and left me stranded. WTF??

But then yesterday it started in the early afternoon. Then I come back at 5pm and it would not start.

Today it started again in the early afternoon, though it was a sputtering start and it almost didn't want to. But it did. When driving around town it shows no signs of sputtering, it runs and revs like normal.

No codes are being thrown. I don't want to drive it anymore for fear of getting stranded somewhere again.

The only things I can think of are:
1) My 4 month old aftermarket (Carter) fuel pump is crapping out on me.
2) I need a new camshaft position sensor

Anyone else have this problem and solved it? I haven't gotten an opportunity yet to test fuel pressure.

 

Get spray bottle and put some fuel in it and keep or in the back of the truck. Next time it happens open the throttle butterfly and give it 5 good sprays then try to start it. If it tries to start you know you're not getting fuel. Figuring out which system is faltering is half the battle. If it happens to be not getting fuel put some vice grips on the return fuel line and see if it will start if so then the fpr is out.

 

It turned out to be my crankshaft position sensor.