I already replaced the fuel pump,fuel filter, and did a tune up.
i was having issues with my chevy S10 about a year and a half ago- i threw about $750 bucks at the problem- distributer cap, spark plugs, computer, coil- etc. etc. nothing solved it until i took it to a mechanic friend of mine and we started tinkering around in his shop- i told him i replaced the ignition coil (while squeezing it) and my truck sputtered, he smiled and pinched it again and said you replaced this? truck sputtered again and died- what it was , was the ignition coil WIRE had a short in it- when i would hit a bump while driving it would move the wire and my truck would stall out.
fixed the problem with a $2.50 junk yard wire from a salvage yard.
once your truck is running begin wiggling wires and see if anything happens.
We need some more information. What kind of truck is it? Was it turning over before you replaced these things, or just after? Does the motor crank? Is the fuel pump actually working, and are the fuel injectors?
It could be that you have a bad sensor; cam position sensor, throttle position sensor, crank position sensor. Maybe the coil pack is bad. Or, perhaps you're not getting a spark... but if you do have a spark, then it's definitely the computer needing to be replaced. Sounds expensive, and if you take it to a shop then you'll pay a pretty penny, but you could easily go to a junkyard and salvage a computer for about half the cost.
Also, it never hurts to check and see if that battery is still good.
Could have to do with the alternator, when my alternator started to go bad my car was slow to start up and eventually wouldn't start up until I got it fixed.
rusty axel oil needs to be applied