04F150

I need to do a fuel pressure test on my 2004 F150 with the 5.4L.
Is there a designated place to hook up a pressure tester? I looked around the fuel rails and didnt see anything. Also what should my pressure be? I am getting lean codes and cant seem to locate any vac leaks using a can of carb cleaner. I just changed the fuel filter and the problem still exists so I am guessing low fuel pressure from the pump or a vac leak I didnt catch.

Kattumaram

One of the fuel rails, usually on the passenger side towards the rear, should have a Schrader valve stem on it. That is the fuel pressure monitor port.

Fuel pressures should be: Engine Off, 30-45psi
Engine Running, 27-42psi.

The pressures can be anywhere within these limits; if close to the lowest rating the PCM will know what to do and compensate by holding the injectors on slighty longer. Injector problems usually are not the culprit causing lean mixture readings; instead look for vacuum leaks, tank pressure/evap system troubles or bad HGO sensors.

And good luck trying to find room to work under that @#$%!! hood.

04F150

Sorry to sound dumb but I have been buying new vehicles the last few years just so I wouldnt have to work on them or hope not to send them to the shop. what exactly is a HGO sensor? I tried the old fashion method of spaying a can of carb cleaner around the intake and hoses and was told that doesnt work because the PCM compensates for it. So I guess that leaves me in need of a smoke machine to test for the leak(s)?

Kattumaram

HGO or HEGO sensors are located at the rear of the exhaust manifolds or in the exhaust pipes near the manifold connections. Four-sensor systems have an additional set of sensors mounted behind the catalytic converters.

Here's a site that will be of interest to you:

http://www.fordfuelinjection.com/?p=31

Good luck

Good old Bill

If your 04, 5.4L has the PCV valve located in the valve cover, suggest checking all the rubber elbows for cracks and deteriation. Do not know what year Ford moved the PCV to the intake manifold and is not serviceable. This was a major concern for vacuum leaks.

04F150

I have crawled over every inch of this thing except the part of the brake booster vac line that connects to the back of the intake manifold because I cant see it or get my fat hand down to it. I tried using propane to try to find the leak just because I cant stand the fact that I am letting this thing beat me. I am going to try to get it into my friends auto shop tomorrow so he can diagnose it for me and hopefully it is something I can fix myself. Until then I am giving up.