Air/Fuel Mixture Adjustment and Fuel Pressure help

My car, an 85 930 Turbo, keeps fouling out plugs (all of them) and I think I’ve narrowed it done to either to much fuel pressure or an air/fuel mixture problem.

I would like to know the best way to properly set and measure Air/Fuel mixture on a 85 930 Turbo. It’s a euro spec edition so I don’t think it has an O2 sensor.

What tools/device will I need to do the measurements/adjustment? What type of readings should I be getting?

What is the proper fuel pressure for a 930? Can this be adjusted without buying an adjustable fuel pressure regulator?

Any advice would be greatly appreciated.

I think that the 930's up to the 1990's ran CIS. Go to your local B&N and get a book by Bentley called "Bosch Fuel Injection and Engine Management" A great book with tons of info on both CIS and Pulsed injection systems. This will tell you all about how they work and how to set them up. For mixture you probably need to use an EGR, or a Dwell meter hooked to the O2 sensor (By 85, even Europe was probably using these). For fuel pressure, you need a guage to go into the line. This is not adjustable, but you can check if it is at the correct pressure.

Hope this helps.
Nick.

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Nick Shumaker
1982 911SC Coupe

[This message has been edited by Nickshu (edited 03-01-2001).]

AMG,
Lower fuel pressure will cause your cis system to go rich. You can adjust the system pressure but requires some disassembly of the fuel distributor(it's in the manual) Hovever, if your fuel pump pressure is set correct in the first place, the settings don't change. From your past posts, I believe you have an after market fuel enrichment device, this can cause a reduction in pressure and cause the fuel system to go rich. So can a clogged fuel filter.
1. you must have a clean fuel filter.
2. if you have any enrichment devices they must not be in effect when checking your pressure.Disable or bypass.
3.check pressure (off hand i don't remember what it is but its easy to look up.
4. After your fuel pressure is correct take your car in to a porsche garage that can do smog tests. Have them set the mixture. They should have equipment better than you can get. Once the mixture is set it dosen't normally change. Actually it would be better for you to let them check the fuel pressure and the set the mixture. This is a time when a garage with the proper equipment can do a better job than you can.
BOB W.