Operation
The FRPT sensor measures the pressure and temperature of the fuel in the fuel rail and sends these signals to the PCM. The sensor uses the intake manifold vacuum as a reference to determine the pressure difference between the fuel rail and the intake manifold. The fuel return line to the fuel tank has been deleted in this type of fuel system. The relationship between fuel pressure and fuel temperature is used to determine the possible presence of fuel vapor in the fuel rail. Both pressure and temperature signals are used to control the speed of the fuel pump. The speed of the fuel pump sustains fuel rail pressure which preserves fuel in its liquid state. The dynamic range of the fuel injectors increase because of the higher rail pressure, which allows the injector pulse width to decrease.
Removal & Installation
- Release the fuel system pressure.
- Disconnect the battery ground cable.
- Disconnect the fuel rail pressure and temperature sensor electrical connector and vacuum tube.
- Remove the bolts and the fuel rail pressure and temperature sensor.
- Inspect, and if necessary, install a new O-ring seal.
- Installation is the reverse of the removal procedure.
Testing
Fig. Fuel rail pressure and temperature sensor pin identification
| FPRT SENSOR TEMPERATURE, VOLTAGE, AND RESISTANCE SPECIFICATIONS | |||
|---|---|---|---|
| Temperature | Sensor | ||
| °C | °F | Volts | K Ohms |
| 100 | 212 | 0.47 | 2.073 |
| 95 | 203 | 0.54 | 2.405 |
| 90 | 194 | 0.61 | 2.800 |
| 85 | 185 | 0.70 | 3.273 |
| 80 | 176 | 0.80 | 3.840 |
| 75 | 167 | 0.92 | 4.524 |
| 70 | 158 | 1.06 | 5.351 |
| 65 | 149 | 1.21 | 6.356 |
| 60 | 140 | 1.38 | 7.584 |
| 55 | 131 | 1.56 | 9.091 |
| 50 | 122 | 1.77 | 10.949 |
| 45 | 113 | 1.99 | 13.252 |
| 40 | 104 | 2.23 | 16.123 |
| 35 | 95 | 2.48 | 19.720 |
| 30 | 86 | 2.74 | 24.253 |
| 25 | 77 | 3.00 | 30.000 |
| 20 | 68 | 3.26 | 37.332 |
| 15 | 59 | 3.50 | 46.745 |
| 10 | 50 | 3.73 | 58.911 |
| 5 | 41 | 3.95 | 74.745 |
| 0 | 32 | 4.13 | 95.501 |
- Connect the vacuum hose to the FRP.
- Disconnect the FRP sensor connector.
- Turn the key ON, engine OFF.
- Measure the voltage between the harness connector pins.
- The voltage should be as shown in the chart, according to temperature.
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