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Dr J Dr J is offline
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Join Date: Apr 2008
Location: Miami
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Did a bunch more tests and I found the following:
Pump current draw is 9.5 A

Replaced fuel filter: This gave a higher pressure (about 0.3 bar)

I took the FD return line to the fuel tank and put a container and repeated the test. Again the injectors flowed about the same 150-160 ml per injector with the same amount in all cylinders. This time there was no turbidity in any of the gas. The FD return to the tank dumped 1.8L in the one minute test.

This tells me that there is plenty of gas coming in but it is being dumped right back into the fuel tank rather than going to the injectors. For this test, the WUR was connected and at 3 bar control pressure.

Wouldn't changing the pump just dump more fuel back?

Since this is an SC FD with the plastic hoses, how much more CIS fuel pressure can it support?

BTW, there is only one fuel pump on the 911 SC
1979 SC, Slant nose wide-body cab conversion. AEM Infinity EFI. Whipple Supercharged!
Old 01-18-2010, 01:16 PM
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