Jet-Black

Hi everyone, I am new to the forum,

I have a 2004 F150 8 cylinder 5.4 . The truck starts fine but after 5 minutes, an entire bank dies out, to later come back alive after the truck is shut off and rested. I believe it is bank 2 (in front of the steering wheel). The truck keeps running - crappy but running- on 4 cylinders only. Do you guys know if the fuel system is pressurized to a fix psi from start, or does it increment as demand of fuel increments? Thank you for any light you can shine my way. I will be checking for electricity being delivered to the coils.
Thank you,

Tommy J

Any codes?

F150Torqued

Welcome to the forum. YES the fuel system is pressurized to a fix psi from start. The PCM reads Fuel Rail Pressure and manifold vacuum, sends a signal to the Fuel Pump Driver Module - who drives the fuel pump to maintain a constant pressure to the injectors (RELATIVE TO INTAKE VACUUM). The injectors should have a constant 40ish psi across them from inlet to nozzle. And YES - Load demand reduces vacuum - PCM tells FPDM, and it increases % duty cycle pulses to fuel pump - fuel pressure increases - PCM senses that via Fuel Rail Pressure sensor and gets all happy.

Your symptom description sounds vaguely like a failing Phaser locking pin - AND/OR - idle oil pressure might be sagging below the level necessary to hold bank 2 phaser at zero retard. If this happens, valve train drag will drag the cam to retard position and reduce power balance of all cylinders on that bank. It would feel like they were missing. THIS however, as @Tommy J suggested, should produce a code - like P0022.

redfishtd

Thats a puzzling post , how do you know the whole bank 2 drivers side is down . We need exact codes . Yes you should check power standing on cops and injectors . The fuel rails are in parallel so i would not expect a fuel delivery problem . This is an on demand system no fuel pressure regulator .
The cops and injectors have standing 12vdc positive with key on ,the pcm pulses the ground to each item separately . Yes you could have lost timing on one bank due to a broken phaser.
The 12vdc hops from one cop /injectors so yes you could have a bad/intermittent connection ,use a test light that will draw load .Shake all wiring . Look for rodent damage to harness .

BareBonesXL

It should be on sequential injection (independent cylinders) at idle speed. The only thing that would be "banked" at idle would be the camshaft.

Doctorgilli

The first step is figure out if it is the injectors or cop's that are failing to energize. Once this is determined we can dig deeper and it seems as though the fault might be in the realm of wiring heating up due to the engine running. I would expect codes to be present as well.