Not starting after cleaning plug leads

Hi everyone, I bought a 87 XJ40 barn find for a good price and was running but missing so I pulled the injectors and found one was cracked and not working. I replaced with a second hand injector form the same model and bought a brand new battery. It was running well. I wanted to clean the leads but after staring it was missing again so I thought that maybe I messed up the firing order. So following an online diagram with number 1 lead at rear I used the following order 1-5-3-6-2-4 Now the car won’t start no spark at all. I checked fuses but can’t find any issues. I opened the driver side footwell and seen that someone has been into the electrics but the car was running. We had some heavy rain and I found water in the foot well. After some reading I removed the duckbill and yes it was full of mud now water is draining well. I cleaned most of the connectors but to be honest the wiring is a bit intimidating and I don’t want to just pull plugs for fear of breaking old wires but I checked them and dried everything with compressed air. Still nothing. Could this be the alarm? The key had a an old battery which I replaced still nothing. I have not yet unplugged Ecu. I hope someone can assist I really want to get her running.

Hi welcome to the forum, no idea why you have no spark but the lead configuration you used was for the old XK engine, yours is a different beast (AJ6) and #1 plug is at the front of the engine. Just move the plugs to the correct position and all should be good.

Hi Robin, thank you very much I will do so and let you know.

Firing order does not affect the production of spark.

You need to review what has been done and make sure the findings are repeatable or not.

Time to start over from the beginning.