UK Car Repair: 1999 xj8l, return valve, pressure fuel


Question
QUESTION: My car sounds as if it cant get any gas to start, it will every now and then try to fire an then stops, I can also hear a whirring noise near the throttle body. could this be the fuel pump?

ANSWER: It could be a fuel problem, but you have to do some basic tests of spark and fuel pressure.  The pump is in the tank, what you might hear is the return valve opening (if it is faulty)allowing fuel to go right back to the tank.

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QUESTION: thank you for your timely answer, could you tell me what the pressure should or if I uncouple the connection should i get a constanst flow of gas with the ignition on because it's not connected to the throttle body?

Answer
Pressure should be 30 - 50 PSI, You need a special gauge to check it while the car is running/turning over.  With high pressure fuel systems you have to be very careful. I suggest you take it to a mechanic, but, if the system is working, there will be very high pressure in any line that is opened!