Xstryker

So my dads 04 f150 screw 5.4 3v ran rough with no power this morning and he shut it down and now it wont restart. It has codes p0021 p0300 p0171 p0174 p0345. Ive already replaced both cam position sensors and cleaned the actuators still the same condition. I am getting 70 psi at the fuel rail pressure sensor, and when i pull the coil pack im getting spark. Any help would be appreciated.

redfishtd

mileage ,mods, location etc your age . That all helps determine problems . For instance, dusty arizona's versus edmonton canada .
Right now it seems like you may have one or more vcts stuck open . Engine combustion dirt in oil causes cam timing problems as it is run by the pcm using dirty engine oil pressure thru the vcts hydraulically moving cam phasers varying cam position timing . Tiny screens in there get clogged and come loose .
Problem is the PCM is trying to compensate at the same time by varying all kinds of things . Injector pulse width etc .That causes more codes .
You have to keep engine oil very clean and use mc filters from wally world with a good drain back valve . 820s I believe but the dirt is already jamming stuff up at this point . You may want to put new updated OEM VCTS in her and see .
Sparkplugs and boots have to be in very good shape , plugs have to be torqued to 25-28 foot pounds as loose plugs cause all kinds of problems .
Inspect your engine wires as rodents chew on them etc . Look for vacuum leaks .

redfishtd

They go bad and corrode thru . New ones are on plastic stand offs . VERY common problem worse in salt country .

Xstryker

If the fpdm did go bad would i still be getting fuel pressure when cranking the engine?

redfishtd

Mine drove me crazy at all the wrong times . In the left turn lane on busy hwy clogging the light for many minutes .
Mine also had gasket problems in connector after I put a new one in it .
The fuel rail pressure sensor sends signal to fpmn to pump up but if corrosion and water in it , is not likely to work .

gone postal

You might have pressure, you might not. To isolate if it's a fuel problem, spray starter fluid in the intake and see if it starts running.

Hold it....coil pack? Is this a new body style '04 or a heritage o4?

nrivera04

Im curious of this myself. How are you getting a fuel pressure reading?

Xstryker

Reading it with my snap on modis ultra and it is a new body style also i did try spraying in starting fluid still not firing up, any other ideas?

gone postal

Next dumb question: Is the light on the dash (red LED by the A pillar) flashing rapidly when you try to start?

Crank position sensor?

Xstryker

I replaced the crank position sensor ill have to check about that light. What would that light mean?