I have a 2001 f250 super duty extended cab with the v10. Over the past week it has been running fine and it will all of a sudden lose power and dies. I've been able to start it back up once right away and a few times it started up after a few hours of messing with it.

So, after the truck dies it will crank and crank but will not start. We have checked fuel pressure and nothing. Then we applied direct current to the fuel pump and it turns on. Then we applied direct current to the fuel pump slot in the fuse box and got a fuel pressure reading of 40 psi. But when we crank we have no pressure.

Update: when we apply direct current to the fuel pump slot in the fuse box the truck will only crank and not start.

Not sure where to go from here. What are your suggestions if I remember any more information I'll post with updates.

 

So we are thinking it has to do with the injectors or spark. Just not sure why? And why this would be happening at the same time. Maybe computer?

 

Have you had the truck scanned for error codes? How many miles are on it? Does it do anything odd before it stops running?

 

Redford,

I had the truck scanned after this has happened for the 3rd time and there were no codes. The truck has 164000 miles on it. When the truck dies I'll be driving aND it will lug quickly twice and die. It doesn't matter if I give it gas it happens in a 2 to 3 seconds and it has no power.

 

That's a puzzle. Is there any other information that can be provided to maybe narrow the cause?

It sounds like maybe we can eliminate lack of spark as the cause, only because a spark failure is more like an on/off switch.

 

Just trying to figure out why when we crank the motor it's not building pressure buy when we apply direct power to the power distribution box the we get fuel pressure but the truck still won't fire.

 

Here some suggestions;

During cranking, fuel pump is energized ONLY for about 2 seconds or so ,by PCM.

Did you verify you have spark (by removing a spark plug and actually seeing the spark during cranking . ( If no spark ,test crank position sensor ).

Your 2001 should have a fuel pump relay (behind radio ?) . See if you have 12 Volt at "fuel emergency shut-off valve -passenger side firewall ) when cranking (only about 2 seconds) . See if fuel pump receiving 12Volt (may be a bad fuel pump relay ).

Good luck,

 

If the truck does not at least fire with a shot of fuel or starting fluid the problem is deeper than the fuel pump circuit and can be difficult to narrow down if it won't stay broke long enough.

I recently went through the same thing with a friends 99 with a 5.4. You need a wiring diagram, a good one from the Ford service manual. My friends truck had already been towed in to a local shop multiple times. They changed the fuel pump, then the next time the truck died they said the pump was bad yet again, parts under warranty, labor was not of course.

The next round of stalling, he had it towed to my shop. I started testing, no fuel pressure and the fuel pump was getting no power. Figured it was the relay so changed that out right quick, the truck fired right up. It ran for 2 weeks without a hitch, before doing the same thing again. Problem was the truck would do that. It might die 5 times in one day, then run fine for days, even weeks. When it did quit it would usually start back up right away or after an hour or so. Not long enough the problem could ever be pinpointed.

Finally it stayed broken long enough. I got out the diagram and started following the fuel pump circuit, then found that the circuit that energized the pump circuit had no power, then the circuit that energized this circuit had no power either. I kept tracing back and realized the ECM was not even getting power.

Even though the very first thing I had done was to check every fuse, I found a 30 amp fuse in the under dash fuse panel that had power on one side but not the other. As I touched the fuse with the probe, I heard a click and suddenly it had power on both sides. I pulled the fuse out, it looked fine, put it back in tested again and everything had power. I turned the key and the truck started right up.

On examination I found the fuse to have one terminal that seemed like it was a little loose. I split the plastic off with a wood chisel and the fuse fell apart in two pieces. I split a brand new fuse and found that a 30 amp fuse is pretty tough even without the plastic cover, no way it was just gonna fall apart. This one apparently had a hairline crack in the fusible link that made it appear to be good but intermittently lose connection. With a new fuse installed the truck has ran perfectly for 2 years.

He spent a ton having the fuel pump changed twice and was left stranded and had to be towed at least 6 or 7 times, all over a 50 cent fuse.

 

After chasing our tails for a day or so. We bypassed the inertia switch and it still cranks but doesn't start. After running the battery dead and recharging it. We decided to start back from the start.

When the key is in the on position we have power and lights but no check engine light.

Next hooked up the code scanner and it couldn't read the ecm. This faulted three times before moving on

Next we text the power to the pcm relay at the power distribution box and could only get 10 volts on one terminal facing the drivers side fender. 10 volts at the blower motor relay and nothing at the fuel pump relay. Which makes sense.

Does the pcm relay only get power to one pin slot?

Our next stop will be the powers and grounds at the ecm computer as it must not be getting power. Anyone know where they all are?

 

Some early Super Duty's had a problem with a windshield leak above the General Electronic Module, above and in front of the parking brake. The leak can cause corrosion in the connectors to the module, and even inside of the module. Look for water stains with a flashlight.


You may want to pull the connectors off. They are a pain to get to but may be worth checking, as well as the cab-to-engine bay wiring harness connector below the steering column behind the left front fender. A corroded connection in either place could cause an intermittent problem like you are seeing. Our '01's are 15 model years old!


I did mine chasing a ghost on my ESOF system, and I survived! I did not have corrosion, but found several threads that referenced this problem.


I think it takes a 10 mm socket to release the connectors. Remove them, inspect them and re-install, being careful to get them on straight before pushing them into place. And GOOD LUCK!

 

I went through this exact problem with my 2000 f250 v10 this spring. the truck would run great and suddenly die but would restart. I had no codes, I could hear the fuel pump prime before start up and had good fuel pressure.
It did this about 6 different times before finally giving up the ghost for good. It was the fuel pump intermittently going out.
luckily I was just down the street from m house.

 

This is not a fuel pump problem.

This is also not very (but possibly) likely a problem with water leaking into the GEM or fuse box. I say "not very" because only F30 is in this fuse box and it is INDEED critical to engine operation.

It's a problem with the PCM not powering up in the first place when the key is turned from OFF to RUN, a process that is mandatory for the engine to run.

Troubleshoot as follows assuming the check engine light does NOT come on when the ignition switch is in RUN (Note: You will be bouncing back and forth from the underhood to the underdash fusebox. PAY ATTENTION!)

SHORTCUT: DO THIS FIRST! Swap the PCM Power Relay for another in a non-critical function. See if now fires up. Otherwise, proceed.

UN-POWERED CHECKS:

1. Ignition OFF. Pull fuse F30 in the underdash box and inspect the contact pins for spreading, burning, corrosion, or pushed into the box. TEST the fuse with an ohmmeter. If no concerns found, reinstall fuse and go to #2

2. Repeat for fuse F24 in the underhood fusebox. If no concerns found, reinstall fuse and go to #3.

3. Repeat for the PCM diode in the underhood fusebox. If no concerns found, reinstall diode and go to #4.

4. Repeat for the PCM Power Relay. While you have it out, make a note of which relay pin numbers are which in the socket. If no concerns found, reinstall diode and go to #5.

5. 2. Repeat for fuse F5 in the underhood fusebox. If no concerns found, reinstall fuse and go to #6.

POWERED CHECKS:

6. Make a careful observation of the PCM Power Relay when the ignition switch is turned from OFF to RUN. A light fingertip on the relay's case can usually tell you if it's energizing or not, it will also make a "click" sound. Be certain of your assessment. If the relay "clicked", go to step #9. If it did not, go to step #7.

7. Ignition to RUN. Measure BOTH test points of F30 with the voltmeter. Should read battery voltage. If good, go to #8. If not, troubleshoot ignition switch circuit.

8. Pull PCM Power Relay out (Ignition still in RUN). Measure for battery voltage at pin 86 of the socket. If none, check PCM Power Diode. If good, check ground circuit from pin 85.

9. With ignition OFF use the voltmeter to, verify battery voltage on BOTH test points of F24. If no concerns found, reinstall fuse and go to #10.

10. Ignition back to RUN. Verify battery voltage on BOTH test points of F5. If no concerns found, reinstall fuse.


This is a basic outline of the procedure I follow. There are assuredly some gaps and probably some errors since I just wrote this off the top of my head. If there are gaps, proceed through the list, record your results, and indicate where the test "falls out" of the normal flow. I can then expand on that issue with more detailed instructions. If there are errors. let me know so I can correct them. My poofreading[sic] skills are sometimes sketchy.