Does anyone actually know what the fuel pressure is supposed to be on a F150 4.6 Fuel Rail. I have $100+ of books and It gives me every spec one can imagine until it comes to atually giving the value of what pressure is expected on the fuel rail.

 

28 to 40 psi, and it should go up about 5 psi if you remove the vacuum line from the FPR. This is for the pre-04's that use a FPR on the rail and not a FPDM.

 

Below 29 lbs at the rail is bad. Your idle should be @ 32 lbs +.

If by chance your regulator goes south, - max is 65 lbs before the PCM shuts the injectors down.

 

I have a random misfire code, my innova device has freeze frame data, says at the time the code was tripped fuel pressure was 126 psi?

 

What are you working on?

 

2010 f150 4.6L

 

After 2004, there's no regulator on the rail. The FPDM turns the fuel pump on and off, and pressure will vary.

 

I'm staring at a 2008 ford f150 with 4.6l v8 it has the fuel pressure regulator on the passenger side of the fuel rail.

I have a question though. If you unplug the vacuum line from the fuel pressure regulator, and your live data shows no change... is that a bad fpr?

 

That's not a regulator on a 2008, it's a pressure sensor.

 

Misfire codes usually mean faulty coil packs, depending on the cylinder that it's a misfire on