fuel pressure problem - runs lumpy

[Seight-V8]

HIya all,

Well this must be the last of the my problems i've had to solve to get this monster running.

Flapper efi fuel pressure set at 36psi with engine not running.

When engine runs with vacuum to FSI pressure regulator disconnected fuel pressure is constant 36psi.

Engine runs sweet & rock steady.

When engine runs with vacuum to FSI pressure regulator connected then fuel pressure drops to 24psi.

Engine runs very lumpy & stalls.

Is my power boost valve suspect?

What should the vacuum pipe connected fuel pressure be at idle with a power boost valve?

36 or 26psi?

Thanks for any help

scott richmond

[Seight-V8]

hiya all,

set the fuel pressure when its running to 36psi, and engine running alot smoother.

Will have this checked out when i have it tuned, very soon hopefully.

Otherwise running at last after 4 months of headaches, and mot booked for tomorrow.

scott

[Alley Kat]

Sorry no idea about the EFI but good luck tomorrow!

[ramon alban]

What should the vacuum pipe connected fuel pressure be at idle with a power boost valve?

36 or 26psi?

26psi at idle and on overrun = hi vacuum

36psi at full throttle = lo vacuum

Or anywhere in between depending up engine load (manifold vacuum)

[Seight-V8]

hello again,

Well went straight through the mot, no problems.

But while it was there ask the mechanic to test the col levels.

And on idle co level was only 0.25%, so running lean on idle.

Looks like i need to increase the co level abit, this might help my lumpyness also.

Car ran great though, blew some cobbwebbs out on the way back, cannot complain about the amount of power available.

All the hard work was worth it in the end, i now have a smile again.

thanks for everyones help.

scott