In answer to your question, YES low fuel pressure WILL kill injectors on a 6.0L. If 4 to 5 injectors were bad, I would be questioning the maintenance history of this vehicle, as well as the quality of fuel used. The root cause of this type of failure is usually lack of consistent fuel filter replacements and/or the use of poor quality aftermarket filters (particularly the ones that don't have the water separator element on the primary filter). Lack of regular oil changes will also cause early injector failures in the long term as well. This is why I always recommend oil change intervals on these engines the same as a gas engine.
As far as replacing the fuel pump itself, all that is required is a 13mm wrench (for the three nuts) and the line coupler release tool (for the two lines on the engine side). This should be a relatively simple task. As far as the injectors are concerned, you will need to remove both valve covers (eleven 12mm bolts/studs each side), as well as a thin wall 19mm twelve point socket to push the injector connectors through the rocker arm carriers. You will also need a TX-30 bit and driver to remove all nine high pressure oil rail fasteners and a 10mm allen key to remove the standpipe and dummy rail plugs on each bank. Once removed, you will need a LONG TX-40 on a socket to remove the one fastener that secures each injector. To install, lubricate each injector o-ring with clean engine oil, and torque each injector to 24 ft-lbs. Torque all nine high pressure oil rail fasteners on each bank to 10 ft-lbs. and the dummy rail plugs and standpipe to 60 ft-lbs. Although I haven't replaced one yet, I highly recommend replacing fuel pressure regulator as well, since it has recently been updated to regulate fuel pressure to a higher pressure. Your shopping list below, will consist of all the Ford part numbers for the parts needed:
Fuel Pump (PFB-93)
Injector (CN-5019-RM) x 8
Dummy Rail Plugs (-W302195) x 2
Updated Fuel Pressure Regulator (3C3Z-9T517-AG)
Cetane Booster (PM-22-A)
Anti-Gel/Lubricity Additive (PM-23-A)
After all this is said and done, change your fuel filters REGULARLY with the proper Ford FD-4604 fuel filters, and oil and filter as well with the proper FL-2016 filter and Ford/Motorcraft 10W30 CJ-4 rated engine oil. And most important of all, use GOOD quality fuel along with the Ford PM-22-A and PM-23-A cetane boost and lubricity additives.
Last edited by m-chan68; 04-01-2010 at 08:00 PM.