fuel pressure problem

[Mark Brokaw]

my fuel pressure is actually lowering when i give it gas while it's in park.What would cause this?

 

[Mark Brokaw]

found out this is normal.disregard

 

[VadersV6]

This is not normal. When you blip the throttle, the FP should jump up. I had this problem once, with the FP dropping when I blipped the gas. The next time I went to the gas station, I discovered I had no gas cap. I had left it at the previous station. I guess it must have had something to do with a lack of gas tank vacuum...or pressure. Not sure which.

 

[87gnblackdemon]

Same problem here. So is this normal or a gas tank pressure issue??? Anyone?

 

[DMan]

When you blip the throttle, you are allowing more air into the motor for a moment. More air means less vacuum. Less vacuum should mean more pressure out of the fuel pressure regulator. What happens if you remove the vacuum hose from the regulator? What happens under boost?

 

[TurboDave]

When you blip the throttle, you are allowing more air into the motor for a moment. More air means less vacuum. Less vacuum should mean more pressure out of the fuel pressure regulator. What happens if you remove the vacuum hose from the regulator? What happens under boost?

Blipping the throttle, yes, but only for a small instant of a second. If you just push the throttle down some, you'll notice vacuum increase as the rpms are coming up with no load.
Also after the initial blip the vacuum immediately starts rising also.