Need Help with 96 GMC Jimmy

[selvington02]

I was wondering if anyone can help me with my 96 Jimmy. It recently has been on the fritz. It is having trouble starting. I first changed the fuel pump and it was running but would take a bit to start. I then replaced the plugs wires rotor and cap and it didn't help with the hard starting. It then would not turn over whatsoever I replaced the CAM and Crankshaft Sensors and that didn't seem to work. I tried hooking up an ODB II to see what the computer would say and I can't get a reading at all, just gives me a couldn't connect message. If anyone has had similar troubles or Ideas about to do next let me know.

 

Thanks.

[babydeuce]

I was wondering if anyone can help me with my 96 Jimmy. It recently has been on the fritz. It is having trouble starting. I first changed the fuel pump and it was running but would take a bit to start. I then replaced the plugs wires rotor and cap and it didn't help with the hard starting. It then would not turn over whatsoever I replaced the CAM and Crankshaft Sensors and that didn't seem to work. I tried hooking up an ODB II to see what the computer would say and I can't get a reading at all, just gives me a couldn't connect message. If anyone has had similar troubles or Ideas about to do next let me know.

 

Thanks.

 

 

First thing is first...a possible reason your scanner cannot connect is blown fuse for the cigar lighter/aux circuit, that is where the interface connector pulls power from. Second, what brand fuel pump did you buy? If it is not a Delco or Delphi, chances are it is already going out, the cheap pumps are notorious for not lasting long, they bleed off pressure which will cause your starting issues. Third, check your fuel pressure on the rail, if it is not at least 58 psi when it primes, it will be hard to start. Watch the fuel pressure without starting the engine, if it drops more than a pound or two over 5 minutes, you have a pump issue or fuel pressure regulator that is going out. Fuel pressure regulator is located under the upper intake plenum.

 

Jack

[riccnick]

Not sure if you resolved this or not, but check the ground wires for the motor to the battery, and the one in back for the motor to the body. Had the back one break on me, and it would sometimes start, sometimes not. Couldn't find a pattern to it. Realized the ground strap was just hanging there, replaced it, and problem solved.