Help finding fuel pressure sensor

[joezek]

I'm trying to locate the fuel injection pressure sensor on my 08 Expedition. I bought the sensor, but can't find where it's mounted. Normally they would be mounted on the injection rail. Mine however just looks like the injectors are the only thing on the rail.

This sensor probably wont fix my ongoing problem but it won't hurt to try. The ongoing problem is strange. Basically if I floor it from a complete stop it takes off and goes fine. But if I roll away from a stop and then step on the gas it just doesn't accelerate. In fact the harder I step on the gas the worse it gets. It's acting like it isn't getting gas. Ive done a TON of work to try and figure it out. The engine runs perfectly smooth and quiet. As it's barely accelerating it will basically feel like I flipped a power switch around 4K rpm and suddenly it wants to accelerate. COP's and plugs are new, all cylinders are firing. The fuel pressure is great at idle but I don't know what it's doing while driving. The fuel pump/filter is new. O2 sensors and Cat converters are brand new. MAP sensor and air filter brand new. I performed a pressure cleaning on the injectors with the engine running for 10 minutes.

 

[Aggiesrok]

Could be trans related, lots of things will retard the engine. There was a recall in mid 3rd gen trans for a software update to fix the car stumbling on acceleration and didn’t throw a code. Sounds like the engine is in good shape.


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[Trainmaster]

You had the problem with both the old coils and the new coils? Check for saved codes?

Check throttle body for smooth throttle plate operation?

 

[Mikezr]

Not sure who sold you that sensor for an 08 but I believe it's all built into the fuel pump housing. Dont take my word for it thou I've been wrong a time or two. It sounds to me like it's a issue with the drive by wire throttle control maybe. I would check the throttle body and see if maybe the problem is with it

 

[joezek]

I've been watching pedal & throttle positions on the live OBD software and that's all good. There aren't any misfires, running smooth. I programmed the OBD scanner with all the PID's to follow the VCT variable cam timing to verify it's been working- and already changed the VCT solenoids. I'm not completely sure about the VCT yet if it's working or randomly kicking on. However in the meantime, I plugged in an X4 calibrator and ran it's stock computer upgrade, and set the correct tire size to fix the speedometer, adjusted the shift pressure etc. Since doing that it feels like a gained over 100+ HP or something absolutely crazy. The truck will snap your neck slightly now and will launch even at half throttle. I can merge into traffic now without even worrying if it's gonna go...So I do think what Aggiesrok was saying about transmission software may have definitely had something to do with it.

BUT it's still not fixed completely. As it's accelerating there are a few dead spots where it kind of hangs, then suddenly it decides to accelerate strong, then hang again.

I have the VCT eliminator kit and will soon install it, maybe that's the final problem. The VCT eliminator kit locks the cam timing, and then reprograms the software throughout the power curve. The dyno results they all advertise show what looks like a peak HP decrease of about 5hp overall BUT a huge increase earlier in the power curve by about 20 hp and tq at much lower more realistic RPM's.

We'll see what happens....