It blows black smoke wen i get on it real hard and it also does it wen i let it sit and idle it dies sometimes

the temperature sensor often causes symptoms such as this. it incorrectly tells the computer that the engine is cold and needs a rich mixture which results in black smoke and hard starts. another cause for such a condition is fuel injectors that are dribbling rather than atomizing fuel spray.

Ok, it sounds as though your fuel pressure regulator or injector lines or injectors are leaking. What engine is in the vehicle? Is the engine light flashing? Does it start hard and blow smoke on startup?

You'll have to get the scanner or code reader to work. Make sure the cig lighter fuse is good. Once you get the trouble codes you can proceed.

there is a very common issue with bad distributors in nissan pathfinders,xterras.and quest. just replace the distributor

Replace your hose going from intake to brake booster ( vacuum leak) check all other hoses also. Clean the throttle body. And a tune up probably wont hurt either.

youll think im crazy but change the oil and look for a oil leak, prob around the fuel filter

you have leaking fuel injectors they are fouling out plugs.

coolant temperature sensor boken, check and replace if defective.

the starting problem could be head gasket if it got really hot..... black smoke wouldn't be oil, and gas would stink but not black smoke if it's old, it wouldn't really matter if it had been sitting for 4 months. black smoke is probably caused by a gas mixture problem, or maybe a stuck fuel injector.