When i drive my truck hard i get a strong smell of raw fuel in the cab. I have changed the plugs and then after about 100 miles i rechecked them with a torque rench. The smell was there before i changed the plugs. Does the fuel pressure increase when you floor it? If so can i pressurise the fuel system with out the engine running to check for leaks?

 

Evap purge valve possibly stuck open?

 

 

If you are smelling it in cab I would think leak is up front . Good chance its orings on injectors . You can pull the whole fuel rail out still connected and put newspaper under it and look for drops . Reinstall using motor oil on orings , Its not a hard job to do . Place some newspaper under fuel filter to see if its there .

 

 

Injector. Not a static atmospheric pressure like a tire . The vacuum created in cyl etc . I am not explaining it very well but I understand the principal .As it sets with key on I think it will run around 40 psi . Torque pro gives you the running pressure from the pcm ..
This system uses a fpdm module on rear axle, the various inputs lets it make a decision to run fuel pump . This eliminates need for a return line or fuel pressure regulator . There is a sensor on the fuel rail that is vacuum assisted to sense acceleration , This sensor feeds fpdm also ,it has a gasket so that is a potential leak point .
Fpdm only has electrical inputs . Fpdm is a high corrosion fail item due to electrolysis if yours isn't bad it most likely will be . New ones are on plastic standoffs to prevent aluminum steel contact .
The most common fuel smell complaint is caused by lose plugs as I am sure you checked for plugs should be torqued to 25 -28 foot pounds . If you pull fuel rails change all orings which are available from local box stores . Carefully blow out area to stop trash from going into intake . Motor oil on orings make them easy to plug in . If over 125k mi I change injectors for new not reman . Leaking injectors can damage engine easily . They are a heavy duty cycle part .
I see you had trouble with the vent line on your gas tank could they be related .
If your gas purge emissions system in trouble it should be setting codes .It checks for a leak by applying vacuum .You have a purge solenoid back on the axle ,some guys have had that trouble as well as rotted lines in this system.

 

Thanks Redfishtd. I will check the lines this weekend. I think i will try and get it on a rolling road so i can look under bonnet while under load. Yes the vent pipe came off a couple of months ago so may be the tank is pressure in it. When i bought the truck about 6 months ago (2000 miles) there was no gas filled cap on! I will also check the control unit on rear axle to see if it is corroded up