1999 Chevrolet Blazer

Hi,
I just read about your problem with your blazer and I had the exact same problem.I took my Chevy Astro to a mechanic and he changed my fuel pump and I got my van back and it quit again driving down the road after hitting a hole in the road. Had to have it towed again. He took the gas tank down and checked the fuel pump again.(Hard Wired it) and it was working. Put it back together and It ran again. Only to quit within hours of getting it back again. He said it was a wiring problem but wasn't sure where it was. Got my van back. Drove it again. Got about 65 miles and guess what happened. DIED AGAIN.I called him and he told me where he had been checking wiring. So I got under my van and found a round plug like device that had wires on both ends in front of the gas tank.(This Plug had wires that went to the Fuel Pump) at the driver side of the transmission (not on the trans but at the end of it) fastened to the frame of the vehicle. I wiggled all the wires and tried to start my van. It worked. While it was running I got under it and tapped on that plug and it quit again. Long story short. There was a wire going to that plug that looked ok but where it went into the plug, the wire was broken but I couldn't see it for the casing around the wire. Moved it again and started right up. Tapped it and it quit again. Problem Found.I kept moving the wires one by one. One end at a time and by process of elimination.I found the bad wire. I bent it over and tied it down to the plug so that it wouldn't move and you know that it has not failed to start since.7 Months Later.I should have gotten the plug changed and probably will shortly. I hope that this information is helpful. And I hope that is your problem also. The fuel pump job costed me $500. I'm sure that yours was expensive.

The wiring problem the other gentleman found was most likely an isolated incident caused by something catching the wire. Two other areas to check would be the 'fuel pump relay' usually located under the hood. This relay is in turn usually wired to an 'oil pressure sensor switch' on the engine. If oil pressure drops too low, the switch will cut power to the fuel pump relay to protect the engine from low oil damage. Either the relay may be going bad or the 'oil pressure sensor switch may be going bad, unless you have a problem with a worn engine using a lot of oil and not maintaining pressure. Oil pressure at idle should be around 20 lbs and about 40 lbs driving down the road. If they are significantly less, then this could trigger the pump relay to shutoff. If oil pressure is fine, then my first guess would be the 'fuel pump relay'.