My 95' Dakota won't start!

:cry: Hello, I own a 1995 Dodge Dakota Sport 4-cyl, 5 speed, 2.L 99,000 with fuel injection. I'm really am stumped on this. On and off in the last couple of weeks, my truck would hesitate for a second and then run fine. Didn't think too much of this until the day after christmas when I was driving to the store at night, the truck was again losing power (only for seconds at a time) and I noticed the lights (all lights) would dim down and come back up. I was scared to completely stop at this point but then thought it was the alternator going out. Well, 30 minutes later, in the parking lot the truck almost didn't start up after shopping ( it did after 5 or 6 times of turning over the engine and flooring the gas, it started but had a rough idle and then smoothed out). I made it home a little scared. The next day, I called a friend out to come and look at the truck. We drove it around the block and it ran perfectly. Nothing seemed to be wrong. My friend noticed that my battery cables were loose on the battery and he felt that was my problem. So we took off the terminals, cleaned them and put them back on tight. I was shocked to learn that my truck now won't start. My friend unscrewed the fuel cap (to the gas tank) it started up but ran very poorly, back fired and sputtered. He let up on the gas and it died. I still can't get it to start. I have replaced the coil, the pickup coil, the distrubitor and rotor (which the rotor was clearly bad and burnt) Truck still won't start. I have no idea what could be wrong. It seems to "Try" for the first 2 or 3 turns of the engine then nothing. I tested the (new) coil spark it seemed that it sparks once or twice and then stops. I'm really confused! I would like to have a heads up before it goes into the shop. I'm a pizza driver and have been using this truck a lot lately for about 3 solid months now. No problems with beebop (truck's name) until now. Thanks so much! -Shana