Help diagnose crank but no start condition....Fuel Pump or FPDM ?

Wade2006FX4 said:

Hi my fellow Mustang enthusiasts, I'm a Fox Body man myself, My very first Mustang was a 1986 GT with the 5speed manual...of course. I sold it to a classmate back in 1988 after my pop splurged and surprised me with my dream car for graduating high school, a back 1988 Fox body GT, hard top, again..with the 5 speed manual of course! I was very reluctant on selling my 86 GT, it was silver with the bullet hole aluminum wheels, that was the first year Ford put the roller cams in the GT's too! I did quite a bit of upgrades to that car and it was a hoss! But in my buddies defence, he did actually beg! I'm now about to turn 51yrs old and still have my 88 GT, my wife and I have 2/kids both of which wanted to drive my 88 to school when they got drivers licence.. Afraid Not!! Sorry y'all I'm rambling! My reason for signing up with this group is mainly due to the Mustangs, but I also own a 2006 F150 FX4 extended cab truck with the 5.4, 3 valve Triton engine, it's got almost 130k on it and I just did a full timing job on it. Phasers ( FomoCo ) brand, guides, tensions ( metal ) not the plastic ones, new tensioner arms chains, and a new Meling high output oil pump. It was my first time working on a phaser engine and it wasn't too bad, I did all my research and didn't do it until I was satisfied I was ready and had all of my parts to knock it out, i bought the timing tool and the cam.phaser removal and installation tool. I took my time and checked everything no less than 4 times, once I was satisfied I pulled the pins on my new Melling metal chain tensions and prepared to close it back up. so I got it all back together and was finally ready to start her up, but before I did fire it up I left my Cps unplugged and spun that baby until I had good oil pressure and I felt it had pumped oil to the top of the engine, I plugged my cps back in, hit the key and Wow!! No chain flamming on the front cover, it no longer sounded like a 7.3 power stroke and was idling like it did when it was new!! Y'all just bare with me, I know it's dragging on, but im getting to my point. So.. I get ready to take that first loop around the block, got out in the road and it was sluggish and didn't have enough power to pull a greased strong outta gnats behind! So I'm figuring..well the pcm has to relearn everything so I just pushed on! Well, it just ain't working out that way.. I started researching the symptoms and my thoughts were throttle position sensor.. Put one on it and it ran better but quickly returned back to running like garbage..so I'm thinking throttle body, so I put a new one on it and it ran the best its ran in a long time. So me and my buddy take off to town to pay some property taxes, on the way it ran ok, was still a little sluggish but had that good pick up after it got going. We got into town and did our business and the truck just kept getting worse and worse, give it some foot feed and it just acted like it was gagging! But would eventually catch up after a few spits and sputters. On our way home it just slowly got even worse and at one point it would only do about 40-45 mph until it just finally took a great big ole...well you get it, it shut off and this time it would not crank back up, acted as if it was starved of fuel, so, I have it towed to my house, and put a new MAF sensor and FRPS on it, changed the fuel filter, it was a little dirty, but I seen way worse! Still nothing, just spin, spin, spin! However after sitting over nite I could go hit the starter and it would fire up but it shuts right back down after burning what few vapors that must be making their way into the intake. The fuel pump is coming on every time I turn the key to the on position, Folks..im stumbled on this one, unless the FPDM is going bad, or the fuel pump has gotten weak I just don't know!! I connected my scan tool and I'm getting no codes, all fuses and relays are at best working, the fuel pressure with the key on was showing about 34 psi but it was steadily dropping, and it was dropping fast, when I turned the engine over the fuel pressure jumps up to around 70psi. My question is, will the FPDM still allow the fuel pump to cycle at start up, but not send the correct amps to the pump in order to run? Or could it be my pump has gotten weak and isn't building enough pressure to crank? I already checked for vacuumed leaks and I couldn't find any right after the initial start up from doing the timing job, the plugs aren't old at all I replaced all of the roller followers with new OEM ones so their all good, new cam position sensors, the cps is working as the tach is moving up to about 200RPM as it spins. Any....and I mean any help will be much appreciated on this cause I am at the end of my rope with this thing, and I really love my truck!!! I know this is my first post and boy is it a whopper! But hey I am a thorough individual!

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