S13 RB26 starts and idles very low then dies...Helpp!!!

[GTR_240SX]

So I just got my car back and like any other person I had to test the car out. As I was testing out the car it pulled hard and everything but then started to bog and as soon as I came to a stop it turned off... At first I thought it was a gas issue.... Went to fill up and the car starts but won't go passed 4000rpm's...

Problems I'm having:

1. Car starts and idles very poorly and dies...?

2. When on I step on the gas a bit and it puffs out black smoke...?

3. Again all this happened after I took the car out for a drive.

Problems I think it might be but not to sure:

1. MAFS wires might of melted together(highly doubted)

2. Spark Plugs

3. Vacuum leak

4. Head gasket might be blown...:/

Please if you guys know anything that can help me out let me know PLEASE.... I will be highly appreciated.
Hope to get this car back on the road very soon... Your help is very much needed.

Thanks,
Conan B.