[Diy_efi] Fuel pump run time with key on

[Mike]

At 04:26 PM 8/22/05, you wrote:
>Ben,
> 
>your EFI system should have an anti-vapour lock one-way valve designed to hold pressure in the fuel rail.  Sounds like it is not holding pressure, and may require replacement.

Is the valve really designed to be an anti-vapour lock, the whole point about
a high pressure fuel return system is to reduce chance of vapour lock
and provide sufficient pressure for the dynamic range of injectors...

ie. The high pressure fuel pump in my car (Nissan/Holden) has an inherent
non return valve by virtue of the recirculating ball mechanism.

The engine works fine if this non return valve effect doesnt work but the pump
will draw more power and it takes a few seconds longer for it to build pressure
on a cold start - this doesnt necessarily mean the nonreturn valve is specifically
designed to be an anti-vapour lock device. I think the vapour lock prevention
is a nice side effect for hot starts however, having said that:-

On my car there is also a surge tank which holds the highest fuel pressure
on last boost and feeds this to the fuel pressure regulator during hot starts
as I have a turbo and underbody average temperatures are higher...



Regards from


Mike
Perth, Western Australia
VL Commodore Fuse Rail that wont warp or melt !
Twin tyres for most sedans, trikes and motorcycle sidecars
http://niche.iinet.net.au







> 
>Will C
> 
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