Hi all and thanks in advance for any advice. 4.3 CPI had the fuel pump replaced last summer and, spider was replaced last year. Had no issues until this weekend when the engine cranks but won't start. Had to get it towed to the garage and the mechanic got it started and said the problem was with the aftermarket alarm system that's been installed for over 15 years! My son picked up the car and drove it to work but 4 hours later when he finished the car did the same thing. Mechanic towed it back to his garage and it started right up. Took the car back, started fine 3 times and today it's doing the same thing again. Not comfortable going back to this garage as you might imagine but really cold out. Any thoughts would be appreciated

 

For starters, get the thing running. Now go open the hood, look down under your throttlebody kind of in behind the alternator. You will see there is a small wire harness coming out of the lower intake with a blue/red wire combo. Grab hold of these wires and push/tug on them and see if you can make the engine stall or stumble.

If anything happens, you have a shoddy injector harness. Good thing is that its an $8 part but you have to open the upper plenum to solder on the new harness. Its not a hard job, and not something you should be paying the mechanic for.

And if this is your problem, go ask the mechanic for your money back.

 

Thanks, would that keep the fuel pump from priming after you turn the key?

 

No, it will keep the injector from firing. How do you know the fuel pump isn't priming. Your mechanic seems terrible if he can't figure this out.

 

That's why he is my former mechanic. My guy sold his shop so I tried this new guy who was close. I have voltage for 2-3 seconds out of the FP relay when you turn the key but the pump doesn't engage. We installed an aftermarket pump last year and I'm beginning to suspect it was a mistake. It could also be a bad ground I guess but the ground feels tight on the frame. I'm not buying the alarm comments he made

 

ok, look by your brake booster, you will find a single wire with a connector on it tats not hooked up to anything. I think its pink or orange... This is the fuel pump replay bypass. Use a jumper wire to give this single wire 12v straight from your battery. If you get nothing in the pump with this method, your pump is shot. Check the pump ground first though, its attached to the crossmemer just behind the bumper/live plate.

And usr a genuine delco/delphi pump to replace. Costs a little more but this won't happen again.

 

Thanks...it warmed up yesterday and the car started right up!. I was able to move it into the garage and it worked again. I still suspect the pump is faulty but at least I can get under the car in some warmth. I've been looking for a new Delphi or Delco pump assembly and can't seem to locate it anywhere. I found MPI and TBI but nothing for CPI (VIN W). Any assistance locating this would be appreciated.

 

OK, so I found a Delphi HP10005 and HP10004 are supposed to fit the application. DOes it matter?