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BionicBalls · Joined: 05 Jan 2009 Posts: 642 Location: Charlotte, NC

I can't seem to get the car to run right. The timing is set right on. engine rebuilt. I have now replaced the WUR with a brand new one which helped some, but I am still getting too much fuel. I have the plastic gas tank installed which means that I am also using the fuel pump from the 951 as well. I have a few questions I was hoping you guys could answer.

What is the stock fuel pressure supposed to be?

Is it possible that I have too much fuel pressure due to the 951 fuel pump?
I believe it is putting out 55 lbs.

Is there a way to adjust the pressure on the fuel dizzy or do I need to install a FPR before the dizzy?

Thanks guys. As soon as I get this thing running, I will be painting it and taking some pics. I made some custom side skirts that look great!
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1980 924 NA
1982 931

Duncan · Posted: Sun Aug 02, 2009 4:30 am Post subject:

Did you measure the system and control pressure?
It is possible to adjust the system pressure using shims in the pressure regulator ( the valve bolted into the fuel distributor).

Not sure about the 951 pump, but the pressure of the 924S/944 pump is actually TOO LOW.

Duncan

Smoothie · Posted: Sun Aug 02, 2009 5:07 am Post subject:

+1^ The 951, 944, 924S are EFI, and run at a way lower pressure than the CIS 924NA and 931.
55 psi would be approximately correct for control pressure for a warmed-up CIS system. -But system (aka- primary) pressure should be somewhere in the 75-95 psi range, depending on model.
No Haynes? It contains info like fuel pressures.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Ozzie · Posted: Sun Aug 02, 2009 12:21 pm Post subject:

Any excess fuel is returned to the tank on a normal system. Does your new setup with a plastic tank allow this?

If your plugs are too wet and getting fouled you may need to adjust the A/F mix on the fuel dissy. Use a long 3mm allen key in the hole on the dissy.
CCW to lean and CW for richer. Small adjustments though. Its very sensitive.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

BionicBalls · Joined: 05 Jan 2009 Posts: 642 Location: Charlotte, NC

ah so I need more fuel pressure. Hrmmm, the car actually does clear up some as I drive it so I guess I'll look into a more powerful fuel pump. So putting in shims raises or lower the fuel pressure?
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1980 924 NA
1982 931

Smoothie · Posted: Sun Aug 02, 2009 2:38 pm Post subject:

Ya, but obviously don't mess with that. Make sure the pump is alright.
Your 55 psi reading could be control pressure, or it could be system pressure, depending on how the gauge was hooked-up.
A correct CIS fuel pressure tester, correctly hooked-up, shows control pressure when its' valve is opened, and system pressure when it's closed.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox