My Impala just would NOT start. Luckily I have a fuel pressure gauge in the engine bay and it showed zero pressure. We got the car to the mechanic and after checking the relay, fuses and voltages, they determined the fuel pump was bad. A new fuel pump was installed but the same problem persisted. The tank was dropped again and this time we found that the fuel sending unit had some problems. Note in the picture below how the one base around the one connector pin is discolored. There has been a LOT of heat on that pin.

Note on the next picture how the insulation has been melted away. Again this is a sign of a lot of heat!! This connector goes on the pins shown in the previous picture.

So what happened was with all the heat the plastic in the connector became melted and eventually caused a broken connection between the male pin and the female socket. We don’t know if the heat was generated "because" of a bad connection in the first place, or if the heat was caused because the fuel pump was drawing too much current. The pump had 113,000 miles on it. Note also that this connection is INSIDE the tank with the gas vapors!!

The next photo shows the top of the sending unit. The three wires are black, purple and gray. The gray wire is severely discolored because of the heat. I have not yet taken apart the yellow junction to see if THAT might have caused the heat problem or not. This block might be visible if you have the right combination of mirrors to see on top of the tank with the tank mounted. The wires are toward the front of the car.

If anyone can provide any more insight into this problem, please let me know.

Mike Lukens