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PcarPhil PcarPhil is offline
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Join Date: Sep 2004
Posts: 3,668
Edit: I just noticed this thread is in the 911 tech section, not the 930 section. I'll leave my post here as I believe this info still applies.

I did this with my '87 turbo (which has the aluminum lambda fuel distributor) to simplify the CIS system in preparation for adding the FrankenCIS system. Once I had the system dialed in the car was running so nicely that I abandoned my plans to install FrankenCIS! I did not have to replace my FD, or even extensively modify my stock FD, I just had to do some tuning.

To remove the lambda ECU and related wiring there is a jumper that needs to be added to the wiring on the engine side of the harness. If you do a search here on Pelican you can find the needed info.

Regarding the frequency valve and FD - I simply disconnected the frequency valve wire connector leaving the valve in the FD. Then I adjusted the WUR to get the pressures back to where they needed to be. Finally I adjusted the individual ports of the FD to get the ports as balanced as possible to each other (along with giving a little extra fuel to cylinders 2 and 5).

Having a WB02 sensor and gauge in place made the overall process fairly easy. Having a set of the CIS pressure gauges would be a good idea as well.

If you do all this and find that you're running lean in the upper RPMs (I am not) then you could add the FrankenCIS system to control your frequency valve to add fuel at the top end as needed.

Last edited by PcarPhil; 04-26-2018 at 08:06 AM..
Old 04-26-2018, 07:56 AM
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