truck sat for about 3 years when I went to start it I would turn over and try to start but wouldn't follow through. I found that if I bleed the pressure on the fuel rail with a fuel psi gauge that It starts easier. I also found that the fuel selector valve was leaking were the cap screws onto the body of the unit. I pulled it and and put an o ring in it and cleaned everything on the inside and put I back together. now my truck starts after about 3 tries but its inconsistent. it will run exactly like it used to and then sometimes it wont start at all or it runs horrible, backfiring, wont rev, sounds like its bogging out. can anyone help me figure this deal out? this truck was passed down to me and iv been around it my entire life its never not ran like it was supposed to. T.I.A

 

3 year old gas is baad. If it's the gas from when it was parked you should pump out the tank and put fresh in. Gas separates and shellacs things up,picks up water from the air, fouls injectors, plugs up fuel filters, etc., etc. If it's the old gas it's great that it started at all, but you shouldn't run it all through.
If you already did the gas before you fired it up then you've got a mystery and you'll be doing some troubleshooting.