Weezy,

The in tank pump is a very small single stage impeller pump. If the pump is submerged (i.e. under the fuel level) you may not hear it running. The pump under the car is a single stage rollervane style pump so you should hear a light buzzing or rolling sound. This sound should be similar to the sound of a marble rolling in a coffee mug.

The worst enemy of an electric fuel pump is “dirt” (rust, road dirt, sand, etc). If when the in tank pump was replaced the tank was not completely cleaned out, or if dirt were knocked into the tank then you could have 2 bad pumps. The in tank pump should be able to handle more dirt than the main pump. So I would not think that it would be bad.

Good Luck

Brian
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86 240GL, 86 740GLE & others