Good afternoon, i am new to this forum. i have a 2002 ford excursion V-10. We were out in lake Havasu City 2 weeks ago. We were hit in a very large Monsoon. about 1/2 hour after the excursion started to stall out Randomly. no check engine light is one. took it to the ford dealership and they replaced the battery. no other issues were found. just to mention it does have about 50,000 miles on a new ford motor. they said they can't duplicate the problem. i dont know if the Monsoon was just a coincidence or not. Fuel pump was installed about 4 years also. the ABS light does come on and off also. ( i dont know if they are related)

any ideas?

 

More details on how it stalls, does it just shut off suddenly, like the key is cut off, or does it start to stumble or sputter, and then die after a few stumbles, does it give any hints or warnings right before it stalls, give us every tiny detail even if you think it might not matter.

 

If the hood seal is not it top condition it will let water into the engine compartment and it will drip down onto the back cylinder holes and get the coils and plugs wet causing misfires that come after its wet and mysteriously disappear when the engine is up to temp and the moisture has evaporated. Many caulk the center point of the gasket on the hood seal to prevent this.

 

So the RPM's drop about 1 second before it dies, feels like it is running out of gas, then dies. i do feel it stupper for the second the rpms drop. it will start right back up though. the fuel pump is newer ( about 4 years old) i have been reading about this issue, thinking it might be the fuel pump relay. any thoughts? at 1st i did think it was water related but still doing it a few weeks after now. i would think it would dry up by now.

 

Don’t rule out the fuel pump because it’s only 4 years old, those were the symptoms that my Ex was experiencing before it died completely The fuel
pumps on our rigs are notoriously poor, and prone to failure. What was the stealerships reason for thinking it was the battery causing the stalling?

 

They stated the battery tested bad so it was causing the intermittent stalling. the battery was about 5 year old so it did make sense so i went with it. They claim the computer shows good fuel pressure. i dont mind throwing so money at it, just want to make some educated guesses of what it can be.

 

My first thought reading this was check the fuel pump relay.
Is the above statement about the dealer saying the computer shows good fuel pressure correct?
Our 2002 Excur has the fuel rail test port and I thought the fuel pressure wasn't available to the computer because there is no sensor for it.
Wasn't the test port deleted when the fuel rail pressure was available to the computer in later years?

 

that was what i thought!
i am having them put a new " fuse box " with a new relay in the vehicle. i am hoping this solves this issue. i will keep everyone posted

 

The Fuel Pressure sensor is relative to vacuum pressure, but thats besides the point, on several Ford vehicles now, I have had the fuel pumps get really weak, but still be able to put out 30 PSI when idling without load or engine off, but once you are under power, pulling load, the pump cannot maintain pressure and you loose power, or the pump just cuts out completely after 20-30 minutes of driving and the pump getting warm, then works again once the pump cools down.

This is how I learned to 100% rule in or out a weak or intermittent fuel pump issue.

Step 1
Connect a mechanical fuel pressure gauge to the fuel rail, most of them still have one to my knowledge, and run the gauge to where you can see it while driving, and go for a drive doing some hard acceleration with high RPM and see if the pressure dips and falters and cannot maintain, or if that is impossible because your gauge has a short hose, put someone else in the driver seat, and have them bring the RPMs up to 4000+ and see if the pressure maintains, if the pressure remains good, go to step 2.

Step 2.
Assuming you were not able to detect any problems in step 1, and that your fuel pressure gauge won't easily reach where you can see it while driving, take the gauge and tool needed to connect it with you, and when the stall re-occurs, jump out and throw the gauge on and test it quickly.

My 07 GT's computer reported fuel pressure was always good, yet it would stumble, ping, and occasionally almost die under hard acceleration, and 3 different shops were baffled, including a reputable Ford Dealer, and it turns out it was not their fault they couldn't find it.

Under my own suspicions based on my understanding of the engine and fuel system, I decided to do my own tests, and i connected a fuel pressure gauge to the fuel rail, and ran the hose between the hood and wiper panel, and up to the windshield and propped it under the driver side windshield wiper so i could see the needle while driving.

Then I took the car out on the highway outside of town in the booneys, and i ran the **** out of it to get it nice and hot and warmed up completely, and did a U turn back the other direction Wide Open to the floor as i rolled through the gears, its a 5 speed manual, and when i got to third is started sputtering, pinged once or twice and i felt the pull power drop out as it did, but what i saw on the gauge told me why, the fuel pressure was wildly dropping, shooting back up, dropping for 2-3 seconds below 10 psi, then shooting back up to 40 PSI, then back down to zero, and shooting up to 30, it was all over the damn place, long story short, the pump was malfunctioning under high load, but only significantly once the car was fully, and i mean fully hot and under load, pulling lots of power.

I took it to the dealer because i didn't want to mess with dropping the tank, told them to replace the pump even though the computer says its fine, do it anyway essentially, problem vanished and has not been seen since, pumps don't always fail dead, sometimes they get dementia, or just sit there and have seizures randomly.....

Not sure if that is anything like what you are seeing happening, but thought it might help.

 

Our 2002 Excur & 2003 Exped have the fuel rail test port, but I thought I've read in 2004 or later the port was deleted when the pressure regulator was added.
I've seen a spacer plate that goes under the regulator that provides a port for a gauge, but it's pricey.