Jaguar Repair/firing order
87 Vanden Plas 4.2
Regarding your answer:
lets follow the original Jaguar sequence and call the last cylinder #1. Remove that plug only and remove the large white w/red tracer wire off of the metal relay on the fire wall and be sure the car is in "Park". Rig a short jumper wire from that spade connector in the wire end and either use it to touch the (+) post of the battery or connect up a remote starter button if you have one.
Now place your thumb over the plug hole and "Bump" the starter a little at a time until you feel compression on your thumb and stop and have someone with a light look at the timing mark on the front pulley and lightly "Bump" the starter a little at a time until you see the marks line up close to the TDC pointer. 5 or 10 degrees off don't matter. If you over run it just put your thumb on the hole again and try again until you are sure close to TDC of the Compression Stroke of #1. To confirm it put a coat hangar wire down in the combustion chamber to feel the top of the piston.
Now (if you are 100% sure you are on the compression stroke and close to TDC,) remove the distributor cap and look at where the rotor is pointed. Put that longest plug wire in that position in the cap. That is Jaguar's #1 plug. Now place each wire in the cap going in the counterclockwise direction around the cap with the wires for the firing order (153624)
is not the rotation clockwise?
That is correct and a more politically correct way of doing it. In the dealership we just used the quick short cut due to time as we were all paid by commission. Yes, Jaguar calls the rear cylinder #1 and the standard in line 6 cylinder firing order of 153624 is still the same if you call the front cylinder #1 or the British rear cylinder #1.