1) Check your oil dipstick to see if you have water in the oil.
2) Pull ALL spark plugs and see if you are able to manually crank the engine.

Also, when you manually crank the engine, do you hear a metal noise when it stops?

'89 Raider V6, AT, SAS'ed, Dana 44 front & rear, 5:38 gears, NP 231 T-case.
'97 Montero SR, cold weather package, 4.90 R&P, BATTLEZ suspension w/ 2" lift, JAOS grill guard & under body protection, custom rock sliders.