Hey guys, thanks for reading and hopefully helping. I've inherited an 04 fx4 5.4 liter with 178,xxx miles. Just recently had all plugs replaced & new air filter.
It's been running pretty good until I replaced the fuel filter yesterday. I've read other posts on here about this, but I guess I need some clarification on what I've done or whats wrong specific to a fuel filter change.
Immediately after I'd replaced it, the truck wouldn't start. It would turn over but no ignition. It had gotten dark, I was hungry, so I quit for the night as I have another vehicle I can drive.
went out this morning and the truck started up, died a couple times, then started and ran. but I found out as I got on the main road it was barely running. It seems to bog down very bad if I accelerate at anything more than a crawl, in fact I can't go over about 1800-2000 RPM.
as I mentioned, everything was good until I did the fuel filter. I have reset the inertia switch. I assumed it wouldn't start last night because I'd flooded it. But now, of course, I'm not sure.

for clarification:
I'm sure the filter is installed correctly.
I have no leaks at fuel line connections, although I did have some trouble connecting the line from the tank to the filter. It seems to be well attached now, though.
After I put the lines on the new filter last night and the truck wouldn't start, I realized I had a line crimped (the line after the filter to the motor), I corrected that. When it still wouldn't start after that I tried priming the motor by priming the fuel pump multiple times. Because of these actions is why I thought I had flooded the engine.
The truck belonged to my late father, who I'm sure never had the filter changed the 7-8 years he'd owned it. He also never replaced the plugs, which was a real problem as you all may know esp for this motor.


any help is very much appreciated! thank you.

 

Did you unplug the fuel pump before you did the filter? Maybe check the plug for it? Any smell of raw gasoline anywhere?

 

I did not unplug the fuel pump prior. Check the fuel pump for what exactly? I did not smell any gasoline last night, other than what had drained out of the filter. none today, at least no smell in the cabin. Its raining like crazy so can't be 100%. However I drove 25-30 miles today already and no crazy loss in mpg.

thanks!

 

Check the condition of the Fuel Pump Driver Module (FPDM) located under the spare tire, mounted to the frame rail.. the back side will break open and cause your symptoms..

 

No, not the pump, the connection. It's on the frame rail under a shield, left side under the driver's door. But if you didn't disconnect that, that's probably not the problem. Let's start cheap... suppose you got a defective filter that isn't flowing properly. Try getting another filter.

 

I don't know how changing the fuel filter would have caused a sudden failure of the fuel pump, though. I mean, if it were bad prior to the filter change I would've known it, right?

 

No one is saying it caused a pump failure. techrep said the fuel pump DRIVER, not the fuel pump. Little aluminum thing mounted above the spare tire on the frame rail. It's what provides the power that drives the pump. And, to be frank, the OEM one is a piece of sh** that falls apart because it's an aluminum thing mounted to steel. It corrodes and falls apart. Common thing here.

 

Ah, I misread. Apologies. I will check both those things out. I assume that if I put the old filter back on and it runs better then I should get another filter. As for the driver, definitely worth checking out. I'm not sure what my expectations should be on a truck this old, but we had a 2010, same motor and size truck that got around 18-19 mpg. I'm getting 12-14 if I drive extremely carefully. does this sound right?

 

Yeah, it does. Mine is leveled with heavy tires and rims and I get about that on road trips. I think my truck-calculated average right now is 12.6

 

It was worth checking out the new fuel filter. Parts guy gave me the wrong one yesterday, simple mistake but a filter made for a focus would make an f150 run lean lol. Anyway, got the correct one and we're back in business. I'll still be checking out the pump driver, but I'll hold out for better weather.

Again, thanks for the help.