Fuel pressure/pump problem ?

TYCharley · November 16, 2006

I can start up my truck fine but as soon as I let go of the gas it dies. I can drive it all day long but everytime I take my foot off the gas pedal to brake, it just dies right away.

I have 50 to 55 pounds of fuel pressure and I'm wondering if the fule pump might be what is causing my problem.

Any other (less expensive ) things that might be causing this kind of behavior ?

Thanks for any help in this matter.

TYCharley · November 20, 2006

BUMP

Anybody !! Any little tidbits ;-)

GM-Tech · November 20, 2006

What's the eighth digit of your VIN?

TYCharley · November 24, 2006

What's the eighth digit of your VIN?

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It is "J"

Hope this helps

GM-Tech · November 24, 2006

Fuel pressure should be 55-62 psi with the pump running and the engine NOT running. Even just a few psi below that spec can be a problem. You said you have 50-55. Which is it? Is it not consistent?

TYCharley · November 27, 2006

Fuel pressure should be 55-62 psi with the pump running and the engine NOT running. Even just a few psi below that spec can be a problem. You said you have 50-55. Which is it? Is it not consistent?

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The pressure is about 43-45 when only the pump is running and about 10 PSI more with the engine running.

Again thanks for any help.

GM-Tech · November 27, 2006

The pressure is about 43-45 when only the pump is running and about 10 PSI more with the engine running.

You sure you don't have that backwards? Pressure is ALWAYS higher when the engine is not running. As soon as you start the engine and let it idle, the vacuum applied to the fuel pressure regulator lowers the pressure. Cracking the throttle makes vacuum drop and pressure go up.

If it truly is only 43-45 when the pump alone is running, that's no good.

TYCharley · November 30, 2006

The pressure is about 43-45 when only the pump is running and about 10 PSI more with the engine running.

You sure you don't have that backwards? Pressure is ALWAYS higher when the engine is not running. As soon as you start the engine and let it idle, the vacuum applied to the fuel pressure regulator lowers the pressure. Cracking the throttle makes vacuum drop and pressure go up.

If it truly is only 43-45 when the pump alone is running, that's no good.

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My Mechanic says thats the way it is, so I will be replacing my fuel pump ASAP.

As always thanks for your help.