mille44

2003 Ford F150 4x4 5.7L
110,000 miles.
After driving in hard rain on Friday I went to run an errand today (Sunday) and when I started the truck it ran really rough (like having a coil out of a cylinder- been there done that), anyway I immediately shut it off thinking it may reset. Tried to start it again and it won’t fire or run at all.
The truck has sat outside in a couple of really hard rainstorms for the past two days.
Things I’ve done since then:
1) Pulled a spark plug to see if it got a spark when the starter turned over. It did, so I put it back in.
2) Checked the inertia switch in the passenger side kick panel, still in the down position.
3) Swapped 304 (PCM) relay for 301 (fuel pump). Nothing changed.
4) Removed the fuel filter for replacement tomorrow (was a new FRAM @ 85,000 miles).

Observations:
1) I can hear the fuel pump build pressure when the ignition is engaged.
2) I also let the pressure t of the fuel system via the Schrader valve. Fuel squirted out of the valve a couple of inches. Seems like enough pressure.
3) After I hear the fuel pump buzz, I hear a click under the hood and a sound that I can only describe as a BOI-ING. The BOI-ING is the very last thing I hear before turning the key to START in the ignition.
So, my plan is to replace the fuel filter and both of the relays (301 and 304) tomorrow.
What else could I check and what is the BOI-ING sound? I have never heard it before, although I might not have had a cause to listen to it…
Thanks for your help.
-Eric

FX4_Envy

You need to really check your fuel pressure. That may not be your problem but your tests aren't super scientific either. Low pressure will make it run like poo or not at all.

mille44

How do you test the fuel pressure?
What should the PSI be?
How do youu test it?
What would the cause be if it is low?

FX4_Envy

You can check it with a fuel pressure gauge. The gauge threads on to the schrader valve and will give you an accurate reading of pressure. You'd have to check and see what the fuel PSI is for your model of vehicle, usually the pressure on most EFI vehicles are in the 40psi range. If the pressure is low it could be a weak pump, plugged fuel filter, faulty fuel pressure regulator. I'm not saying its the problem but its something that needs to be ruled out.

Engines are real simple they just need 3 things to run, air, fuel and spark (at the correct time). Find out which one is missing and you'll find out why it doesn't run.

bones2o21

i know on the fuel rail of my 97 the fuel pressure regulator is controlled by vacume. no vacume= no fuel alowed into the cylinders. check for vacume make shure all ur lines are good and still connected. i dont know if 03s are still vacume fed or not. on my first truck a 88 f150 straight six same thing as my 97 vacume fed the line broke and i couldnt figure it out i had spark a new fuel pump all that finaly i thought too check that fuel pressure regulator so i put my hand vacume pump on it and the truck fired right up. traced the vacume line and shure enough i had a broken vacume line.

the regulator is on the driver side of the fuel rail silver and round bout 2in tall on my 97 has a single vacume line goin into the top of it. like i said i dont know if the 03s are the same but somthin too check. they do go bad but ur truck is way too new for that but stragne things have happend befor

heres a pic:

mille44

Yup. I think there is one there. It looks similar to the picture but has a red wire/ hose coming out of it. Is that a vacume line?
We're getting into areas that i know nothing about now....

bones2o21

yep my vacume line is red aswell on it. there is a black boot on the end of the red line that slips over the silver end of the fuel regulator port. trace that line make shure there is no breaks no cuts in it. it should plug into the throttle body some were or atleast thats were mine goes.

mille44

So, on the advise of a couple different mechanics I decided to tackle this myself rather than pay a HUGE towing charge to bring the truck all the way into town. Through this experience, I have learned that local businesses/ people are sometimes your best bet for honest and straightforward advise. I will try to practice keeping my business as local to where I live as much as possible from now on.

Here’s what I did:

1) I went to the auto parts store and bought $122 worth of parts to hopefully fix my problem. I bought 8 new double platinum spark plugs, 8 new coil boots (for the Coil Over Plug system that Ford thinks is great engineering…), a new fuel filter and a fuel pump relay (just because I was eliminating possibilities and this relay works for more than one application in the pickup.

2) After I got home, I decided to install the new fuel filter and try to start the truck. Turning the ignition, nothing happened and I realized that I had some work to do. However, because I had a grumpy Chevy pickup when I was in high school that was carbureted, I decided to try to start it with the gas pedal held to the floor in case the carb or the throttle body was flooded. I didn’t know if it would work, but it did and the truck started. It ran, very shakily for a couple of minutes, and would let me rev it up (higher RPMs seemed to run better too). So I let it run for a couple of minutes.

3) After starting it and having it run really rough, I decided since I had nothing better to do for a few hours that I would go ahead and change all of the spark plugs, ignition coil boots and the relay anyway.

4) It took about 3-1/2 hours (at 1:00 in the morning) of skinned knuckles and my best golf language to get her all back together and she runs like a top, so I drove it to work this morning and all seems okay. At first the exhaust really smelled weird, but I think that is cleared up now as well.

5) JWalker offered to use his OBD scanner tomorrow and see if the truck ever "threw" an error code, but the Check Engine Light never came on, so I'm hopeful that nothing else will need attention other than the squeaky rear suspension that I intended to take care of this week anyway.

Now the pessimist in me fears the next rainstorm, thinking that an electrical component that had enough time to dry our for two days will act up again, but I will cross that bridge when/ if I get to it.

Thanks everyone for your advise!

Fingers crossed!

mille44

Forgot to add, the computer reader threw a code of P0351. Misfire on Cyl. #1. Not sure if that was a problem or not (maybe an old code reading), but over a week later, shes runnin' great!