C.I.S. FUEL DIST. ADJUSTMENT-1974 -911
11-03-2002, 05:55 PM
#1
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Location: Worcester, MA
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C.I.S. FUEL DIST. ADJUSTMENT-1974 -911
THE SYSTEM PRESSURE AT THE FUEL DISTRIBUTOR ON MY 1974 911 WITH C.I.S. FUEL INJECTION IS 55-58 P.S.I. IS IT POSSIBLE TO INCREASE THE PRESSURE TO WITHIN FACTORY SPEC. OR DO I HAVE TO REPLACE THE COSTLY FUEL DISTRIBUTOR. IS THIS AN EXTERNAL SPRING LOADED VALVE SCREWED INTO THE DISTRIBUTOR CAST HOUSING OR IS IT AN INTERNAL VALVE? ANY
OPINIONS????
OPINIONS????
11-04-2002, 12:13 PM
#2
You can modify system pressure by changing the number of shims at the pressure relief valve. It's external and screwed into the passenger side of the fuel distributor. Adding shims raises the system pressure, while removing shims lowers system pressure. Problem is that 55-58 is way too low. Each shim only changes the pressure by about 3-4psi. My guess would be a weak fuel pump. I've been inside fuel distributors, and I can't think of a reason why one would fail in such a way that system pressure would be too low.
Ooops. Actually, I just remembered the specs are 65-75. You're not that far away. Both of my 3.0L fuel distributors had 2 shims originally. See how many you have now. Adding 2 may get you to 65psi. Tiny washers work just fine if you don't have access to the proper shims.
Rob
1980SC
Ooops. Actually, I just remembered the specs are 65-75. You're not that far away. Both of my 3.0L fuel distributors had 2 shims originally. See how many you have now. Adding 2 may get you to 65psi. Tiny washers work just fine if you don't have access to the proper shims.
Rob
1980SC
