Hey guys,
My wife's DD is a 296K 2004 Expedition. Just ran into an issue. I am 8 hours away, trying to figure if anybody might have insight to the issue. No codes on a OBD scan.

She was driving it, ran fine(always changed oil at 4-5K miles, recently new plugs/coil packs) until suddenly loss of power. She pushes the throttle and it falls on it's face. Off throttle the car will idle and slowly take off with minimal throttle, but anymore it falls on it's face.

At first, I thought it might have been the computer, disconnected it, power down. Plugged it back it, same symptoms.

Next was the fuel filter. Thought it might have gotten plugged. Replaced it. Same symptoms.

So I am thinking the next step is the cats(original) thinking they might have collapsed or are plugged. Wanna cut them out or go Hi-flows.

Or possibly a fuel pump?

kind of stumped being far away. Any ideas before I cut the cats? TIA,

 

Any smoke when you push the throttle in? My first thought would be fuel filter, fuel pump, or plugged fuel system.

 

No smoke, I was thinking fuel pump too. Fuel filter was changed.

 

When the fuel pump went out on my 5.4 L Expedition, it wouldn't start at all. I had an older Ford that jumped a tooth on a worn out nylon tooth crankshaft gear and threw the timing off. After that the car wouldn't hardly go until the RPMs climbed up. But I haven't heard anything like that on the modern 5.4L.

 

My first thought would be to ask when the coils and plugs were last changed?

 

Less than 2000 miles ago. Plus when I was having issues with them at all, I would get a misfire code. I am getting no codes.

 

Check the fuel pressure before haphazardly cutting the cats.

 

Pressure should be 50 PSI? Is there a schrader valve on the fuel rail? I am not at the truck to check for one. TIA

 

Clogged cats would be more of an issue when you're moving and adding load, not at idle or low RPM situations. Like meboarder said, start by checking the fuel pressure.

 

40 psi with a hold time of 5 minutes is the standard im familiar with.

It should come up to 40 psi the first time you hit the key and hold that pressure for 5 min. If you have to cycle the key to get 40 psi or if it comes up to 40 and bleeds off right away then the pump is bad.

Unless there is something inherently different that has changed on our trucks.

Alloro?

 

Nothing to add, you nailed it.

 

2005 may not have a Schrader valve, as that is the year Expedition went to the FPDM (Fuel Pump Driver Module) mounted to the rear frame.

 

On the '04 model check on the passenger side fuel rail towards the rear of the rail. That's where they are on most of 'em.


-Mike

 

Well, the wife took it to a shop. They agreeed it could be the cats, they couldn't work on it though.

But driving away, trying to get home, the car ran fine, but all the gauges were going crazy, OD light was blinking, and it threw a bunch of codes(PO708, PO750, PO755, PO743, PO141, PO161).

I am guessing the shop unplugged something. Now I have to go drive 9 hours to fix it because I can't trust any of the shops up there.

 

Check fuse 32, it powers some of that stuff. If it's good.... Have the O2 sensors every been changed ? The 0141 and 0161 codes are the aft O2 sensor heater circuits bad (replace the sensors). The 0750 and 0755 codes are tranny shift solenoids. Check the fluid level or when was the last time the fluid was changed? The 0708 code is the gear selector indicator (the PRNDL indicator...). Does it seem to be acting right ? Is there a lot of slop in the gear indicator? After you check all that clear the codes and see what comes back...



-Mike



Fuse 32 is along the top row.... ignore the red arrows, they're for something else.....