HALP! Mysterious, intermittent ignition problem -- '00 Expedition

My husband’s 2000 Ford Expedition has 94K miles and has been very well maintained. For the past few months, it’s been having intermittent ignition problems. It’ll start up fine for a few days, and then suddenly will need several-to-many attempts in order to start. Engine cranks every time, but won’t catch. A few times it has taken over 10 min to get it started, and on occasion we’ve had to take our other vehicle instead. My son and I spent 15 creepy minutes in a dark parking lot the other night trying to get the truck to start. It’s in the Ford repair shop for the third time in a month now (last time was for 4 days), and the shop has been unable to replicate the problem enough to diagnose it. (The two times when it wouldn’t start for them was when they DIDN’T have it hooked up to fuel-system test equipment.) I’m getting the sense they just want us to go away quietly and buy a new vehicle, but this one is the type we like…paid for! The problem occurs at various times of day…in various types of weather…when truck is hot, cold, or in between…gas tank at different levels…we can’t find a common denominator, and all other diagnostics come back fine. The only slightly creepy suggestion the shop had was that maybe someone poured sugar in the gas tank…yikes. Hoping for a less-creepy diagnosis…thanks for any help anyone can provide!

The trouble is most likely due to either an ignition problem or fuel delivery system problem. One quick way to help determine what the trouble is and that usually works well is to spray a small amount of starter fluid into the intake when the trouble occurs. If the engine fires up with that then the fuel system is suspect. The fuel pump relay would be my first suspect in that case. If the engine doesn’t fire up then the ignition system should be checked and I would first want to make sure power is getting to it. The ignition switch may have a problem. Checking the error codes in the ECU should be done also for any clues it may show.

For some reason this is symptomatic of a fuel pump in fords of this age range. The way to verify it is to stop by the dealer every time you pass by and have them check things out quickly if the car won’t start. It is probably a couple hundred dollar job to replace the fuel pump so it is a good idea to verify it is the problem first.

When this problem occurs, turn the key to on for a few seconds, then turn it off for a few seconds. Repeat this process a few times then try to start it. This would be an indicator of a failing check valve in the pump. Another thing you can try is to use a rubber mallet and have someone bang on the bottom of the tank. One thing I will say is that you need to get that away from the dealer and find a good independent shop to tackle this. Chances are they’ll fix it faster and for less money. All the seasoned, good driveability techs I know don’t work at dealers. With the exception of one, and I think he got dropped on his head as a baby. If it is a fuel pump, you will probably spend better than a grand at the dealer. Msrp just for the pump at the dealer is better than $500.00 .

Thanks very much for the tips! I appreciate your help.

Thanks a lot for the info and suggestion…I appreciate your help!

Thanks for the advice…and the much-needed laugh. I will try the key on/key off test next time the problem occurs. Is the idea behind banging on the tank to dislodge some type of sediment that might be in there? Thanks for clarifying.