Jaguar Repair: 85 XJ-6 Wont start, air flow meter, vacuum test

Question
Is there an easy way to tell whether it's related to the battery instead of the starter or fuel pump? Howard, I've read several of your answers, you are really top notch. Thank you for helping all of us. Steve

Answer
Hi Steve,
Preliminary tests are, To test the fuel pump circuit just remove the air filter and manually open the air flow meter flap by hand with the key on. You will hear the fuel running in the fuel rail. This will not check pressure but will check the electric circuit. Check the timing with a timing light and spark by just put the plug wire on an extra plug (thick blue spark). Fuel to the combustion chamber by spraying starter fluid into the intake when trying to start.
Even with a well charged battery connect a second well charged battery up like a jumper battery will test if it is battery related since the Ser. III has a battery issue history.
A "Noid" light will test the injector pulse.
If all this checks ok do a manifold vacuum test and if it fails run a compression test on all 6, throttle open and at least 4 or 5 revolutions on each cylinder.
One of these should show something. Let me know,
Howard