My 98 d1 is 4.0 do you have a distributed at front of engine?

Sensor should be unplug undo screw/bolt holding it to the engine, pull from engine then reverse order

I can't say for sure it the problem with a kit added in like that

 

Yes distributor is at the front. Is there a photo of what it looks like?

 

UPDATE: Ok so I switched it over to petrol after washing the very greasy engine down. The revs have become more consistent! And it is idling much better, not perfect but much better.

???

 

Every 1998 d1 I have seen is 4.0 and does not have a distributer, supposed to be coils mounted behind the intake, I could be wrong

If you have a distributed there is a part in it that goes bad look in the tech section, also check all your grounds, I get the feeling you got a franken rover

Post pics