I need help, fellas
Worked on this all weekend and still no joy.
I bought a fuel pressure regulator (part# XR3Z 9C968 AA - $49.30 list), but it looked like a b!tch to R&R, so my brother suggested restricting the return line to see if consistent pressure could be maintained before we dug into the fuel rail. This took all Saturday as I couldn't get the connection apart at the back of the fuel rail, or next to the fuel filter. EEEERRRRRRR!!!!!! I bought 3 different tools, and sprayed and blew out the connections, but they wouldn't budge. Finally my brother was able to do it yesterday and clamp it off, which raised fuel pressure. So we thought it was definitely the fuel pressure regulator.
Mitchell On Demand 5 said it came off with two screws, but posts on another thread here said it was part of the fuel rail and the whole thing had to be replaced. After much aggravation we found that it was held on by a cir-clip hidden underneath. After another struggle to R&R it, we found it would produce another 10 psi, but it still bled off within a second and wouldn’t run for more than a couple seconds. The truck still only idled with the MAF disconnected, and hog rich (clouds of half burned fuel filled my garage).
So then we went looking for the leak. My brother wanted to pull the tank to see if one of the hoses came off again, but I reasoned that if one had, we wouldn't be able to build 40psi. Then he thought maybe the PCM had a bad injector driver that was holding an injector open. We disconnected each injector, one at a time, to feel for the 'click' and to see if it still lost pressure while disconnected. Everything checked out.
We're at wits end. It's a $100 tow to a competent dealer and $90/hour + parts after that, and I’m cheap!