2002 Gmc Savana

banshee3422 · February 20, 2009

whats up guys im new to this forum im just tryin to see if i can get any help from somebody hopefully somebody else is having the same problem as i am.. well im having a problem with a 2002 gmc savana 5.7L converted to MFI from CSFI the problem for starters is it has a missfire in mainly cylinders 4, 5, and 7 i've changed the distributor because it had some side to side movement with a new cap and rotor that seem to have cleared up some of the missfires in the other cylinders but there are still hard missfires in cylinders 4, 5, and 7 before i started diagnosing the truck i had pulled 2 codes from the computer which are p0101 and p0300 the truck wont even run because of these misfires so its making it hard for me to diag p0101 so i started putting parts in the car so i can atleast try get the thing to run on its own because the way it is right now i have to keep the throttle open to start it and to keep it running as soon as i lift my foot off the gas the truck stalls. i changed the maf sensor the map sensor the distributor the spark plugs even the computer still no change.. i cant really look at some of the sensors reading on my scanner because i cant get the truck to run on its own or at idle and sometimes the computer isnt going through the misfire cycles and making it hard for me to even notice any change in cylinder misfire i checked compression and it is around 150 to 175 i dont really know the spec on compression on this specific engine because mitchell doesn't have info from manufacturer if anybodys sees anything wrong with the specs that im getting please let me know my back is up against the wall with thing and im looking for any kind of help i can get thanks in advance