Compression checking cooling system sounds like a good idea. I think before I remove heads I'll compression and leak down tests the V6.

It seems to be flooding so quickly and badly I can smell unburnt fumes from motor area and tailgate. There isn't any pooling or tank loss I can see. After it sits for 48+ hours or more it will start when I hold pedal to floor. Tonight it started twice, and was only ran for about 8 minutes total. Would not start up on 3rd try when I was going to test transmission in parking lot.

I think the previous owner had it when this Montero started having problems and somehow it has led to it dumping excess fuel into the system. My guess is an injector is either stuck open or on, or like someone else said, something controlling/feeding ECU or injectors emissions info is causing the injector(s) to flood the engine.

But the only diagnostic code I have is the P0300 "random multiple cylinder misfires". Which is common to blown head gasket also, which it seems to have based on water in the oil. So I guess I'll pull the injectors (while I'm getting to everything else), and plugs/coils of course, test what I can, and then DIY clean them with process I saw on YouTube using a battery and spray can carb cleaner. Replace o-rings and screens if I can find kit.

Looking to source a rebuild kit for the injectors. If anyone has used one from a supplier and been happy with quality and price.

Anyone used a good repaie manual for 2002 year?