For the past few months I've been driving my dual fuel Patrol GQ with low power on both petrol and LPG (the petrol's power loss is much more noticeable though).
I got the car earlier in the year, ran fine, and after doing some 4WDing and getting stuck in a pretty deep waterhole for a couple hours the car isn't feeling too well (imagine that).

The car has a rough idle, often dropping down to about 600rpm on a cold start or straight up stalling. Sometimes it won't turn over in petrol so you need to start it in LPG (still needs a bit of a kick too).
Driving around it's pretty low in revs, I often stick the auto tranny in 1st for take offs and even then I can't get over 3000rpm.

I've replaced the distributor cap and rotor, replaced all my spark plugs, and all my ignition leads. I recently started thinking it could be running rich in idle and lean when driving; as after idling I notice a pretty strong fuel smell. Testing the MAF it seems to be perfect, and doing a smoke test I can't notice a vacuum leak.

I'm trying to take a do it myself approach to fixing the car, but it's my first time so sorry if my inexperience shines through. If it comes down to it I'd like to know what sort of mechanic I'm best off approaching, but hopefully you guys can help me avoid that.