My 2005 XJR engine stalls but the rpm steady.
But once I push the throttle pedal a little bit harder, the rpm went down. But the rpm went up normally if I push my pedal really tiny.
So I used the SDD to see there’s no faults about this. The data logger shows the fuel pressure is around 282kpa at idle, it go down around 200kpa when push the pedal.
I already replaced two brand new fuel pumps but the issue still exists.
Anyideas?

 

Was the fuel filter was changed ???
The fuel pressure on both of mine read about 55 psi.
But yours reads about a bit low at 40.psi

 

Yes, the fuel filter should have also been replaced as Wingrider suggested. By the way, were those Jaguar OEM fuel pumps that you installed? If you simply replaced the fuel pumps (instead of the entire sending unit), another possibility would be that both of the fuel pumps were simply incorrectly installed. In a case like that, that is why I would always recommend that the fuel pump be tested out prior to installing the unit back into the fuel tank.

 

sorry mistake, the pressure is fuel rail pressure.

 

the pump is genuine oem for Bmw e39, they are the same part number.
okay I will replace the fuel filter first to see will it fixed or not.

 

The problem fixed today. The bad fuel rail pressure sensor caused the problem.