Hello Gents,

Im repairing a 2004 Jaguar XJR and its got a weird problem.

When the car is half tank the car fuel system shuts off. I hooked up a gauge to the fuel rail to monitor the fuel pressure. We changed both left and right fuel pump in the tank but were still getting the same results. The only fault code I get is 0191 fuel rail pressure sensor A circuit.

Any clues where else to look?

Does any one know why there are 2 level arms one left and one in the right fuel tank?

I did notice when the fuel pump pulls all the fuel out of the passenger side the whole system shuts down. No idea what is triggering it or causing it to do so. The only thing there is the float sensor.

Thanks in advance

 

Since its a saddle tank, the fuel is pumped from right to left when the total level separates the two sides. The level arm is there to control the transfer...and I presume the fuel gage signal. Is there any chance the wiring for the pumps got reversed, so the main pump is on the transfer pump circuit?

 

The balancer system isnt working well, not quite sure whats wrong yet but the plumbing and wiring are correct.

 

I am sure you have seen this, but I'll try to copy the DTC below. What I get is that you should check the fuel filter first, and if that doesn't help, the pump is inhibiting due to a high resistance in the pressure sensing circuit. High likely means the sensor wire is disconnected or the wire is broken, or finally the pressure sensor is faulty.


P0191

IP Sensor to ECM sensing circuit: high resistance, open circuit, short circuit to ground, short circuit to high voltage
73
IP Sensor circuit range / performance
ECM Default:
Fuel filter / system restriction Fuel system leak
Fuel level> 25%
– Default value of 3.80 BAR (55.11 psi, 380 kPa) used
Idle engine 30 seconds
– Fuel pump feedback control inhibited
Incorrect fuel pump output
Drive the vehicle fully warm for 5 minutes and include some hard acceleration and hard over run conditions.
IP Sensor failure
IP Sensor disconnected
IP Sensor supply circuit: high resistance, open circuit
IP Sensor ground circuit: high resistance, open circuit, short circuit to ground, short circuit to high voltage

 

Oh, just remembered one other thing...these Jags do not have a fuel return to the tank, like many other cars do. The pressure at the rail is controlled by the pump. If it doesn't know the pressure, it may be cutting off the pump, believing the pressure is excessively high.

 

Wondering if you have solved this issue. I am working on a car with same symptoms!