Hi all!

I've got 3 ford trucks of various types and vintages and have gotten SO MUCH good information from this site although this is my first post asking for help.

2004 Expedition XLT 5.4, close to 200k on the clock. Truck runs and shifts great. Problem started with in town driving but is now doing it at highway speeds. So intermittent that I can't find anything obvious! It will go 500 miles and run beautifully. Then I'll drive 50 miles and it will die 6 times. Electronics always work. It's not a battery cable. At speeds over 10 mph, I can usually shift into neutral when it dies and it fires up on its own. Without turning the key. In parking lots or at stop lights, I have to pull over and crank it manually a few times to get it to restart. It never hesitates or sputters. Just straight up cuts out.

Since this truck has so many miles, I have started cleaning everything and throwing parts at it. Here is what I've done so far: Removed and cleaned throttle body, MAF. REPLACED: IAC, TPS, PCV. I have visually inspected all vacuum lines and also used a can of starting fluid to spray them all when the truck is idling. All to no avail.

I bought this truck a few months ago and the previous owner always had it serviced at the dealership. The fuel pump was replaced sometime in the last year. Fuel filter looks newer so I have not replaced it.

Has anyone else had this issue? The next step I'm taking is disconnecting and cleaning all the electrical and computer control plugs and sockets.

Thank you you anyone who can offer some experience!!

 

The symptoms you've described are typical of a failing crank sensor

 

I bet you have a burnt "unserviceable relay" on the back of the fuse panel. You can actually de solder it and solder in a new one and it will fix it. That will also save you a couple hundred dollars. There's also guys on eBay that will do it for you for around $100. I just went through the same thing you are. It's the R303 fuel pump relay. Google it and you will find more info on it. Good luck.

 

I wanted to let everyone know that I parked this truck for a while. Ended up pulling the main fuse box and sending to five star repair. An eBay vendor and they did a great job! It was around $65. They checked over the whole box, replaced three relays that weren't in spec and sent it back. The realay that ultimately caused the problem was 203. A soldered in relay that runs the fuel pump relay. After this was replaced, the truck has run great for about 3k milea. [QUOTE=Nate Nidey;16664

I've got 3 ford trucks of various types and vintages and have gotten SO MUCH good information from this site although this is my first post asking for help.

2004 Expedition XLT 5.4, close to 200k on the clock. Truck runs and shifts great. Problem started with in town driving but is now doing it at highway speeds. So intermittent that I can't find anything obvious! It will go 500 miles and run beautifully. Then I'll drive 50 miles and it will die 6 times. Electronics always work. It's not a battery cable. At speeds over 10 mph, I can usually shift into neutral when it dies and it fires up on its own. Without turning the key. In parking lots or at stop lights, I have to pull over and crank it manually a few times to get it to restart. It never hesitates or sputters. Just straight up cuts out.

Since this truck has so many miles, I have started cleaning everything and throwing parts at it. Here is what I've done so far: Removed and cleaned throttle body, MAF. REPLACED: IAC, TPS, PCV. I have visually inspected all vacuum lines and also used a can of starting fluid to spray them all when the truck is idling. All to no avail.

I bought this truck a few months ago and the previous owner always had it serviced at the dealership. The fuel pump was replaced sometime in the last year. Fuel filter looks newer so I have not replaced it.

Has anyone else had this issue? The next step I'm taking is disconnecting and cleaning all the electrical and computer control plugs and sockets.

Thank you you anyone who can offer some experience!![/QUOTE]

 

I did with a different make and model. It turned out to be a failing crankshaft position sensor.