I replaced the fuel filter on my 2005 F150 4.6L and my truck started fine after I replaced the filter. I let it sit for a couple of days and now it won't start. When I depressurized the fuel system, I disconnected the safety shutoff switch and started the engine until it died on me. Then I replaced the fuel filter and reconnected the fuel saftey shut off (red cap with plunger). I pushed the reset button and truck started fine.

Now after a couple of days it won't start. I got a buzzing noise in the fuse box. Pushed the fuel safety switch reset and still buzzed. I thought I narrowed it down to the PCM relay. I pulled the PCM relay buzzing stopped and replaced with a new one and now - nothing not even buzzing noise. I have power to the lights and I have good voltage at the battery. Turned the key and voltage stays the same at the battery. I turned the key and the inside lights and clock shut off and the engine doesn't crank at all. Not sure what else to check any ideas?

 

Being that it is a 2005 I will put money on a bad injector(s) and hydrolocked. if you are under 110,000 miles ford should cover the damage.


Wait that might only be the 5.4....can someone confirm?

 

That's for the 2005 5.4 3v only.....
https://www.f150online.com/forums/v8...ram-07m08.html

 

Yeah thats what I thought. Either way if it wont crank he might have damaged an injector running it dry. Then hydrolocked.

When you try to crank it is there a clicking sound coming from the fuse box?

 

Your truck's battery probably puked on you.....might want to get the battery checked.....turning the key and the lights go off along with the other accessories goes dead makes it sound like the battery.....good voltage doesn't necessarily indicate that the battery has a good load carrying charge left in it....

 

I'll try and get the battery checked but I don't think that is the problem - I put a fresh charge on it a week ago. I am not getting any noises at the fuse box anymore. I was getting a buzzing noise before I pulled the PCM relay (R203)...when I pulled the buzzing stopped. Then I put another relay in...no more buzzing. I am thinking it may have something to do with the alarm system. When I put the key in the ignition, the red light on the dash continues to flash even when I turn the key. Maybe that's disabling it...I tried both my keys and the same thing happens. That would be wierd that both keys are bad.

 

What is the "good voltage" value you are measuring at the battery?

 

Not sure on how to help you on your prob but just wanted to know why you didn't just unplug the battery and pull the line with a rag in your hand to catch the fuel? That's what I did on my 07 4.6 and only took me 10 mins including disconecting and reconecting the battery. Never even touched the fuse or any relays.

 

Well - I guess I learned my lesson. I looked on-line. someone said to lightly hit the inertia switch to temporarily disable the fuel pump (didn't do that) and then someone just said disconnect the switch and run the vehical until it stops running. Next time I change the fuel filter - I'll just disconnect the battery and let the truck sit a little while.

The voltage at my battery was about 12.26 if I remember correctly.

In the mean time - over the weekend I had someone that works at Ford make a house call and ran a diagnostic. His computer could not make a connection with the PCM on my truck and checked to make sure I have voltage at the fuse box... His diagnosis - is that I need to replace the computer. I think that this is just coincidental...but who knows if I would have only just disconnected the battery cable to alleviate the fuel pressure - maybe I wouldn't have had this problem? I feel pretty confident that the computer is the problem since a Ford Technician diagnosed it. I paid 50 bucks and then he'll come back out to reprogram for another 20. So far the best price for a referbished computer was at advanced auto 289 - I think Ford wants 6 to 800 bucks for a brand new one.

 

I have never done anything prior to removing the filter. If it has set awhile, I just remove it and there is never any pressure. Just a few drips that I catch with a rag.

 

x2^

I don't work for Ford but I would think a 12v batt would be similar from one vehicle to another regarding charge values. 12.25v on my Harley batt= deader than he77. Believe it or not, 14v is about right for a fully charged "12v" batt.

 

X3.......

If I'm in a hurry I just depress the fuel rail valve.......

 

You won't see 14V on a static battery. The only time your battery should be reading 14(.4)V is when the engine is running as that is the alternator providing a charge. Most batteries stay between 12V-12.5V at rest.

 

Blown cigarette lighter fuse.

 

glc is the man.