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I have a 1998 Ford Explorer that does not start cranks but doesn't start.

I've replaced the starter and battery so far. After replacing that it didn't want start just cranked. I thought that it may be the fuses, so I took the fuel pump relay out cleaned it a bit put it back in and it started. I thought it just might be dirty.

Couple days later I tried start it and it didn't turn on just cranked so I did the same thing and no start. Before I could hear the fuel pump turning on, now I can't.

So I plugged in the code reader and gave me a code for the camshaft position sensor. Now can the fuse cause my fuel pump not to turn on or is it the camshaft sensor that doesn't let my fuel pump to turn on?

I got quoted at almost $1000 for the fuel pump. Figured I'd ask around for advice.

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  • What engine do you have? 4.0? Single Cam? Overhead Valve? 5.0? What was the camshaft code? Is it pending? Current? Do you have fuel injector pulse? If you can't hear the fuel pump have you checked the fuel pump inertia switch? Can you confirm power to and from the switch? How about fuel pump current? if you hook a multimeter inline or use a clamp meter is the fuel pump drawing current?
    – Ben
    Commented Jan 6, 2017 at 0:02
  • Its the 5.0 .The code was p0340 . i have not checked for fuel injection pulse . Someone checked the inertia switch said there was power going to the fuel . but i would have to check that out my self since he didnt seem skilled and just wanted to go on and change the pump for easy money i assume . i was hoping he would power the fuel pump directly to see if it would turn on but he did not why i was skeptical Commented Jan 10, 2017 at 4:02

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The vehicle computer uses the camshaft position (CMP) sensor signal to do a number of things from engine timing to controlling the fuel injectors. Some vehicles determine when to turn on/off the fuel pump with a signal from the CMP sensor signal. So, yes, a faulty sensor can cause exactly what you are experiencing.

Yes, the fuse or replay can cause issues, but it far less likely. Considering you found a code for the CMP sensor, that is the likely cause. Replacing the sensor is far less expensive than the fuel pump and much easier to get to.

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  • On the Exploder 4.0 OHV the cam sensor is on the backside of the intake and not that easy to get to. Book time is 2 hours. The SOHC version OTOH is easy to get to. The 5.0 similarly is easy to get to as it's on the front of the engine as well.
    – Ben
    Commented Jan 6, 2017 at 0:01

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