Last week i had problems it would turn over but not start. after several attempts it started but would only idle at 1000 rpm. check engine light came on..i shut it off and after several attempts it st

Last week i had problems it would turn over but not start. after several attempts it started but would only idle at 1000 rpm. check engine light came on..i shut it off and after several attempts it started...drove to auto zone and they did the ob2 check..codes said map/maf and glow plugin 3 cylinders...i started it up after several attempts and went to napa to see my friend to tell me what the codes meant...he said this says everything is wrong but doesnt make sense..so ibought a fuel filter and went out to start up my sprinter...it started right up and the check engine light was off....it ran fine even perfect....stopped at the grocery store and when i came out it wouldnt start again..after several attempts it started and i was on my way...no check engine light and ran fine...went home and changed the fuel filter bled the filter and tried to start it ..i killed the battery..so i went and bought and installed the battery...it wouldnt start...i entered the code for alarm and tried again but no luck...when you turn on the key i can hear the fuel pump working so i left the key on and loosened the top of fuel filter and there was fuel shooting out of it..closed the nut and tried to start it with no luck...at this point i have limited funds and i desperatly need this for work...i am mechancaly inclined but dont know diesel or electrical...any help or suggestion would be greatly appreciated thank you ..ray