93 dakots just wont start

got a 92 dakota that just wont start. no matter what. ive replaced that battery, starter,spark plugs, fuel injecters recently and fuel pump about 2 yrs ago. but the truck has been sitting for about a yr. and if and when it does rarely start it just dies. RPM's get to like 500 and then it just dies. all it does it like rururururruururur (bad impression. but i think you got it)it sounds like it wants to turn over but im not sure what else to do. so please help if you can

Is it a 92 or a 93? What engine?
Have you checked to see if it has spark and fuel pressure?

its a 92. 3.9 liter. i dunno if its getting a spark. im assuming that it is thats why its starting once in a while. how do i check if its getting fuel pressure? plus i just discovered that theres a fuel leak in one of the fuel lines. so maybe its not getting enough pressure, or even enough gas to the engine. i dont know a whole lot about cars. the basics.

If your going to assume things are working, then you might as well stop looking for the problem because you'll never find it. You can't assume anything when troubleshooting a problem.

My truck would do the same thing when the cat was clogged.