my sister left me her 4 runner, it ran rough so i took it to the toyota dealership, they said i needed to get the engine rebuilt, one of the cylendars had low compression, so, a day later i checked the oil and it was almost dry, so i put oil in it and it ran alot better, so i went and filled up the tank, drove it home, parked it and went to bed. in the morning i got out to start it and it turns over but wont start. i have no idea whats going on here. please help me.