99 Ranger 4.0 - Fuel Pressure problem

throttle position sensor.

His TPS doesn't have a damn thing to do with fuel pressure. He's on the right track with the fuel pressure regulator. Bob

The fuel pressure regulator is what you need assuming you have made sure the vacuum hose is properly connected. If it does not respond to vacuum at the regulator, then the regulator is bad. Around 35-38 is normal at idle. It can go lower or higher depending on vacuum. I have played with a hand pump and watched the vary between 20 and 45 psi. 65 is WAY too high

You guy's are missing the boat. The fuel system on this vehicle does not have a external mounted regulator and return line; i.e. a returnless fuel system. There are no vacuum lines on the regulator. The fuel pressure specifications are 56-72 psi. The basic engine needs to be checked, ( compression test hot and cold ) before any electronic diagnosis is attempted. It also needs to be questioned of the actual idle quality, does it truly idle rough or is the idle quality the same as the same year vehicle?

I have checked the cylinder compression and all is well; After more research, there is a common issue of bad intake gaskets with the Ford 4.0's.

I plan to replace the upper & lower intake gaskets this coming weekend and go from there....

Yes the fuel pressure is in the right range, the Chiltons book does not describe the proper pressure and is wrong (at least the one I have) so my fuel pressure is not out of range as first suspected.

I think I'll just tuck my toolbox between my legs and disappear into the woodwork.

Why? You were just not aware that there was some evolution.

Things like that make me more aware of my oldfartitis syndrome. Hell, I've even gotten to like my CV almost as well as my F150. I've lowered my dream car sights from a Porsche Carrarra TT to an '05 Stang GT-R but, Raquel Welch is still looking pretty good.

And ya know? She still does.