fuel pump issue

[sonnygn]

turn key on fp goes to 20 psi start car fuel pressure goes to 42 psi shut car off pressure drops to 20 psi is the pump going bad new filter in car helped a little but not much all so going to check volt at pump plug which ones the fuel pump wire should have 12 volt there right

[Keller]

This behavior may indicate nothing more than the internal drainback valve in the pump is not sealing well. I would not panic.

The wiring in the back depends on the year. 1984-early 1986 (black ground, pink sender, and tan pump voltage), late 1986-1987 (black ground, violet sender, grey pump voltage).