Hey guys.am new here to this forum.have a 05 f350 v10.truck started shutting off.at ambient temp of 40 degress.turned it back on gave me a po191.have not check fuel psi.order gauge.replaced fuel filter,fuel pump module.runs also cleaned maf.but today at 40 degree in the morning.starts fine.warmed her up put it drive.stumbled and turned off.had a hard time restarting.once on.i reved it to 3500 rpm.then the idle went low and off she goes.any help will be appreciated.

 

Truck shuts off when cold.gives a p0191

 

fuel rail pressure sensor circuit.

 

Thanks for the reply.doe the fuel rail sensor have anything to do with fuel psi.

 

Im not sure. I will look it up and see what I can find.

 

Possible causes
- High fuel pressure
- Low fuel pressure
- Damaged FRP sensor
- Excessive resistance in the circuit
- Low or no fuel
- Wiring harness connector of the fuel pressure sensor
- Fuel Rail Pressure Sensor
- Fuel
- Vacuum leaks

Read more: OBD2 - OBDII Code P0191 FORD - Fuel Rail Pressure Sensor Circuit Range/Performance | Engine-Codes.com

P0191 FORD Description
The Fuel Rail Pressure (FRP) sensor is a diaphragm strain gauge device in which resistance changes with pressure. The electrical resistance of a strain gauge increases as pressure increases, and the resistance decreases as the pressure decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signal to the Powertrain Control Module (PCM) corresponding to pressure.


Strain gauge type sensors are consider passive sensors. A passive sensor is connected to a voltage divider network so that varying the resistance of the passive sensor causes a variation in total current flow.


Voltage that is dropped across a fixed resistor in series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor.


The FRP sensor measures the pressure of the fuel near the fuel injectors. This signal is used by the PCM to adjust the fuel injector pulse width and meter fuel to each combustion cylinder.

 

Cool thanks.ill just ordered my fuel psi tester with the autometer#3280 fuel rail adapter.i scaned it.and thats what is showed the fuel rail sensor.will check fuel psi and give results back.should ne here jan 4.

 

Oh and welcome to FTE.

 

Thanks ridender333.i will check back with results.

 

Where are you planning on testing the fuel pressure? Not sure, is that adapter supposed to thread into the fuel rail somewhere? There's not a schrader valve on the 3v motors. You need a scanner capable of reading it electronically.

 

Truck has a fuel adapter on the left side of the rail.next to what looks like a fuel regulator