proplen with my 240sx

[johnnywild]

Last week i bought 240sx sr20 s14 engine in 13 car. the engine had low compression and it was missed firing so i took out the cames and i found a problem the the rocker arm was out of its position so i put everithing back on and i started it was still running like sh..t so next day me and my friedns change the head gasket it was running litlle better but after like 5 minutes it dies and when i was changing the head gasket a found other problem the exhaust lifret was moving i could push it in i didnt change it yet. But i have a question on u guys what can that be why is it dying and the fuel pump is probably stock and when i turn the car off and take out the key the pump is still running thank u for comments.

nissan 240sx s13 sr20 red top 300rwhpnissan 240sx s13 sr20 s14 hp????