I have an '01 that had the lift pump die just before the warranty expired. I added a fuel pressure gauge so I could keep an eye on the replacement pump. That was perhaps 18 months ago.

Recently, the fuel pressure has been odd. When I hit the starter, the pressure rises to 10-12 psi but then after starting, the pressure drops to near zero, perhaps 2 psi or so. I have a replacement pump on the way but after thinking about it some more, I'm not sure that the pump itself is the problem. If it were defective, would I be getting that kind of pressure at starter engagement?

I assume that there is some sort of pump controller that governs the pump. Is it possible that the part of the control circuit that runs the pump after starting is defective but the part that runs it at starter engagement is fine?

 

When you bump the starter the pressue is dead heading as there is no fuel being used, once it's running then the pump is too weak to keep up with fuel demand.

 

That makes sense. Thanks.

 

No problem, we've seen a lot of lift pumps at the shop that act like yours.