87 XJS, won't start. Here's what has been done so far and what I've tried. Over the winter, new plugs, wires, cap, rotor, fuel injector hoses, vacuum advance unit. Car started right up and ran good afterwards. Put plates on as I don't drive it over the winter, first drive, no issues. Second trip out, started up and ran, stopped for fuel, would not start afterwards.
When you first try to start it, it fires a couple of times but won't start and it will repeat this after you let it sit for awhile. Installed a fuel pressure gauge before the "out" regulator, 36 psi and it holds. With the ignition on, opening the throttle causes the injectors to click and the needle on the pressure gauge to drop slightly each time you do this.( pump not running).
If i remove the fuel pump relay, the fuel pressure gauge doesn't drop while cranking the engine, injectors not firing? Check the spark, has a good strong spark. Checked voltage at coils, 12.3 volts. Checked the resister for the feed to the ECM, checks out, 6.7 K ohms. Checked the shielded wire for continuity, 1.2 ohms front to back. Checked the wire to ground, checks good. Unplugged the harness from the computer and checked the coolant temperature sensor resistance, about 2.5 K ohms from that end. Cleaned the connector to the resistor pack and checked the resistors, all seems good. C

omputer? New to this Jaguar thing, looking for fresh ideas.