Truck fuel guage drops to empty when in park?

[apegs]

I find this to be a weird issue and I dont consider myself very knowledgable when it comes to mechanics. My 2001 chevy silverado will show an empty tank even when its full when I put in park and its still running. Any body have any ideas on this? When Im in drive it will show the correct amount of fuel that I have.

[Esox_Magnum]

Fuel sensor or fuel pump going out, my 99 jimmy did something similar, once under 3/4 tank wouldnt register... Noticed my 01 did the same as yours the other day once to but been fine since...

[BartmanMN]

Probably just s corroded sensor. My 2000 does the same thing. I don't trust it much so just watch the mileage and fill up around 300 mile mark. Been doing it for 2.5 years and the pump has not failed. You have to drop the tank or remove the bed to replace it.

[jps]

You could buy or make up a pressure gauge. Not sure but I think 40PSI would be a good pressure. I'm sure some one will chime in. Fleet farm may have the gauge. I like the liquid filled but does not have to be. The fuel system has a place to hook in to check pressure. google it!!! jps