Help with a POS chebby- fuel problem

[snake]

Neighbor's fuel pump quit- so I swapped relays in the box, then dropped the tank (the only way to get to the connector). The connector, one of the middle pins showed voltage for 2 or 3 seconds when the key was cycled, so I had power down there at the pump. Since I had power I figured the pump was dead. Swapped it and still nothing- won't zzzzzt up when key is twisted. The thing will run when starting fluid is sprayed in so it is definitely a fuel problem, and the pump isn't running. New part was new, and a factory delco part. Could the new pump be bad? Anyone have any ideas? This has me stumped and I don't like it! It's an '04 trailblazer with a straight six...

 

[martin]

Try putting 12v directly to the pump to see if it runs. Two pumps that are bad is unlikely, When you checked for voltage at the connector where did you take your ground from, the pump needs ground to work.

 

[kcm1582]

We had this happen in the shop once. For ours it turned out to be a bad ground. Try running a new ground wire for the pump and see if that fixes your problem.

 

[snake]

It rained today so didn't get the chance to play with it, but I think you are both right. I grounded to the frame rail when I tested for voltage, and the tank is plastic- so it does need a solid ground to work. I'm going to take a piece of wire over there and add another ground. Betcha it fixes it. I ran 12V to the old pump today and it ran like hell... so a mis-diagnosis on my part. I hate when that happens...

 

[snake]

It was a bad ground, but inside the connector- you could clearly see three metal tabs, the one for the ground was missing... the connector was one expensive sombitch but at least it runs. Thanks for the help!