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Joes924Racer · Posted: Mon Dec 27, 2004 11:39 am Post subject: Fuel return line

Did the pump test like haynes outlines.
Found I am only getting 590 cc or 2 & 1/2 cups of fuel
from the fuel return line after a 30 second run.
Ill switch out the accumilator and get some
more pumps to try.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

Joe,

Why don't you also perform the test at the inlet to the fuel distributor and at the pump side of the filter. That way you can tell if it's the pump, bad relief valve, bad filter or crimped return line.

Dennis
_________________
81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

Joes924Racer · Posted: Tue Dec 28, 2004 11:48 am Post subject:

Rebuilt pump I have now put 1500cc at he filter and 950cc
at the return line. Still runs crappy..Im gonna do a comparative on the injectors at a 100cc.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

Joe,

You should check for a return line blockage or a broken o ring on the relief valve.

Dennis
_________________
81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

Joes924Racer · Posted: Tue Dec 28, 2004 3:00 pm Post subject:

Whats a relief valve, I compared the injector levels
twice once with the senser plate way up and the injectors
really putting out. the levels were exactly the same. I did
the same test pulling up on the senser plate about 3/8 of an inch
only & the the fuel output levels were exactly the same in all injectors.
I then decided to pull the intake and get a new gasket for it. It
would run if you kept on the throttle so Im thinking air leak.
What the heck is a relif valve
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

Paul · Posted: Tue Dec 28, 2004 3:03 pm Post subject:

Its in the fuel dizzy, IIRC you posted that you shimmed it to increase the fuel pressure.

Did you order a CIS tester yet?
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.