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Longtime follower of ScannerDanner's videos and bought his book last year but knowledge still lacks on certain issues. Hoping to get some help on an issue that I'm having a tough time with on my 2004 Ford F150 crew cab with the 4.6. 218,xxx miles. Been a great truck for a couple years but the other night it died on me on the freeway. Started shaking and bucking a bit and just lost power. Coasted to safe place and tried to re-fire but just would crank and not start. Had to get hauled back home on a rollback
Nothing obvious upon visual inspection. As I was waiting for the tow truck I plugged my Scangauge 2 in to see if I could pull up any codes- there were none at the time. Next day I started by checking for spark, which I have. What would happen is it would start, run like crap for a second or two then die on the first try. Any attempts after it wouldn't even try to stumble and fire unless it sat for a bit. Next thing I wanted to check was fuel pressure on the Scangauge 2. Tried unsuccessfully to get it to monitor fuel pressure but when I first hooked it back up again, I found it had P0300, P0305, P0307 and a P0340 cam sensor code. Cam sensor is easy and was only $20 so I replaced that. Still no change. Ended up getting a better scanner that could read fuel pressure off the sensor. Turns out I now had a p0193 fuel pressure sensor high circuit code. Now here's where the weird part comes in- I have normal pressure (38-42 psi) key on/engine off but when I crank it, my fuel pressure goes from about 55 minimum and spikes to 79.8. I work for a parts store so I can get away with a little loading of the parts cannon, so to speak. Tried a new fuel pressure sensor and no change. Tried a fuel filter just to try something plus I don't know the last time it was changed and wanted to do it for maintenance. No change other than it seems like it doesn't even want to run on an initial start anymore. I've heard about some possibilities of wiring issues and a short to reference voltage. I could understand that but why wouldn't the pressure read high all the time even with key on/engine off if that was the case? Don't think I've heard of this before. Any direction and assistance would be greatly appreciated. I'm trying to get this old girl going and running for one last summer before I retire it.
The fuel rail pressure sensor readings you posted sound correct, so I'd say you don't have a fuel pressure problem. If you clear the faults and P0193 doesn't come back after a cranking attempt, I'd put that code aside for now.
The next easiest test would probably be to try to run the engine on alternate fuel. Give the intake a few shots of brake/carb cleaner during cranking and see if it starts. If it starts, find out why fuel isn't getting to the cylinders. If it doesn't start, fuel isn't the problem.
I have a 5.4 3v truck at the shop right now that set a CMP code and barely ran. Little different set up, but the CMP was not making a signal because the chain fell off the right side (bank 1) cam sprocket, which was visible through the oil fill cap.
If I remember correctly, your engine has only one sensor on the driver's side (Bank 2) in the timing cover.
It might be tricky but if the cam sensor code returned after changing it, you could try to look in the CMP sensor hole with someone cranking the engine to make sure the cam gear is turning on that side of the engine.
