Hi My Name is Dave i bought my 1993 S10 Blazer Tahoe series about a year and a half ago . It has a 4.3 cpi engine . The first problem I had was The high pressure line that goes to the cpi at some point someone replaced it with a high pressure rubber hose and clamps . Truck would not start one morning and the engine would not turn over so I remove the spark plugs to see if i could get the motor to turn and I found the number five cylinder full of gas the oil was full of gas . So I removed the plantum . Found the rubber hose almost completely off replaced it with factory line changed oil and filter . Truck ran fine for about a month then the engine went replaced it used . Truck ran good for about four months then it quit and would not start . no fuel pressure replaced pump with a replacement pump from what use to be a quality auto parts store . Put the pump in no fuel pressure but pump is working so removed the gas tank again I took the sending unit and placed it in a clear container with just enough gas to operate the pump and found that the gas was spraying out the pressure relieve valve .Took pump back ordered another one same thing happened .Took that back got my money back went to another auto parts store bought a new pump worked fine four two weeks low fuel pressure took pump back this time I bought the whole sending unit with the pump . Well that last about a month and the pump went low pressure `again checked it again for blockage nothing so took that unit back this went on for a few more times always the same problem .So finally after nine different pumps and sending units I bought an ac / delco fuel pump . Truck ran better than it had since I owed it .That lasted about two weeks truck quit while driving it got out checked for spark checked for fuel pressure had both but no start . Checked for cpi pulse and it was fine so put fuel pressure tester on it again fuel pressure was low checked pressure at the pump and found the pump had the proper pressure so I checked the lines and found what looked like plastic stuck in the high pressure line at the intake unknown what it was or how it got there . Truck started right up . ran for about a week it started to just quit and would not start back up buy accident I found that the connector wire to the intake that goes to the cpi would make the engine quit when I moved the wire I replaced it . Engine started right up every time for a few days now it if it sits for any length of time the only way it will start is to use starting fluid starts right up one minute it seems to run find next traffic light it runs rough . Go to take off hesitates almost dies . Today same thing no start pump is running have pressure have pulse , spark still need to use starting fluid to start in the morning after sitting all night it might start and it might not . I have had to have it towed around fifteen times . It has a rebuilt dist. new starter new radiator brand new plugs, wires , new fuel filter On half the new sending units I put in I found that the hose from the pump to the sending unit was loose the inlet off the unit is smaller then the outlet off the pump and they where using a clamp that was to big Quality control at its finest . At one point I replaced the cpi unit but that did not do anything . I am at a loss as to waht is causing this problem .