Check engine light

[blackthorn]

I recently bought an 03 Marauder through this website. The previous owner had installed a supercharger, and had it tuned by a shop in Sacramento , CA. I have been driving the car daily for several months but recently the check engine light came on. I took it my regular mechanic and the computer read out read "fault fuel rail pressure circuit". He was confused by this and didnt really know where to start. I have continued to drive the car and nothing seems wrong. Does anyone know what this means? Or could you recommend a good mechanic in the San Francisco Bay Area?

[TAKEDOWN]

Maybe a fuel mod upgrade that might be setting it off?

[Pat]

II RC this fault seems to occur more frequently on S/C'd cars, due to the upgraded fuel systems.

To see if the fuel pressure sensor is good, pull the vacuum line and smell for gas. If no smell then the diaphragm is good and the unit is functioning.

However it is detecting something out of tolerance, either lower or higher fuel pressure than the PCM is programmed for. This is an adjustable parameter I'm told.

You can have this parameter checked and adjusted by your dyno tuner or newer model flash tuner.

My car would throw this code, P0190, every few weeks. My tuner sent me a new file and that significantly increased the interval that the fuel fault occurred. I get the fault now every few months. Clear it with my XCal-2 and I'm off and running.

I did change the fuel pressure sensor at one time but it didn't fix anything.

This sensor is located on the passenger side fuel rail at the very end, closest to the front of the car. It's a small 1" square device with a small electrical connector and vacuum line.

Regards,

[RF Overlord]

If you can give us the actual Pxxxx code, that would be helpful.

[blackthorn]

The code is P0190

[RF Overlord]

From the factory service manual:

P0190 - Fuel Rail Pressure Sensor Circuit Malfunction (FRP)

The comprehensive component monitor (CCM) monitors the FRP sensor to the PCM for VREF voltage. The test fails when the VREF voltage from the PCM drops to a voltage less than a minimum calibrated value.

Possible causes:
* VREF open in harness.
* VREF open in sensor.
* VREF open in PCM.

Verify VREF voltage between 4.0 and 6.0V.

I'm at work right now, but when I get home I'll look at the wiring diagram to see exactly where you check for VREF.

[BUCKWHEAT]

I get the same thing & just turn it off with the handheld. It appeared when I went to the 60# injectors and the GT fuel pump.

[RacerX]

Clear the DTCs. See if it comes up again soon after. If it does, replace the frps orhave someone more knowledgeable check it. If it doesn't come back soon after, just keep an eye on it. It could have just been a spike up or down and just an anomaly. Keep an eye on it though.

[omarauder]

I'd change the Fuel Filter first, just on spec...