Jaguar Repair: 84 XJ6 loss of power, continued, tank leaks, vacuum test

Question
Howard,

When I posted the previous question, it was more of a curiosity as the car had run fine this week and I had taken it out on short evening drives, but I am nearly convinced I have a fuel delivery problem. I changed plugs and oxygen sensor Friday night, and the no power condition returned. It will idle just fine, but when throttle is applied, RPM only increases slightly, and I can hear rushing of air, along with a slight backfire within the air filter housing. This usually occurs within a minute or two of starting. I performed a compression test, throttle open, and got a consistent 141 -146 PSI across all six cylinders. I have drained both tanks, which yielded gas that looked like red furniture stain, and am running the left tank on new 87 gas. Right tank leaks, so it gets no new gas for the moment. Noted improvement from this is that it generally starts on the first crank now, no cranking and pumping the accelerator to get a start. I know I should test for fuel pressure - do I tap in to the line leading to the pressure regulator? For the vacuum test, do I "t" in to any vacuum line? Any thoughts at this point? I am the same one that mentioned I can hear the fuel pump running from the driver seat, or outside the trunk when running.

THANKS!

Answer
If you had that much rust in the tank, your fuel filter has to be partially clogged.

Vacuum line "T" can go on any of the vacuum hoses. A "T" on the fuel line is easiest at the fuel line just before the fuel rail. Leave the regulator alone.

Howard