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AndreasK AndreasK is offline
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1977 911s, WUR033, diagnosing 2 main issues.

Advice needed

My 77 911s has had a long lasting cold idle issue. Recently fuel consumption has become painfull. (Norwegian gas prices are through the roof). 1.48 litres pr 10K. Shuld be closer to 1.0. Im also getting popping from unburnt fuel in the exhaust.

Finally got around to getting a fuel tester, and I have run through the tests.

WUR 033
Cold controll 0.75 bar at 10 C. (Spec 1.1 to 1.6)
System pressure 4.8 bar (Spec 4.5 to 5.2)
Warm controll 2.7 bar fron 5 mins and onward (Spec 2.7 to 3.1)
Engine running with vacuum 3.6 bar (Spec 3.4 to 3.8)
Resting pressure 0.5 at 4 min. (Spec 1.3 at 10 mins)

So my cold controll is low. Which explains my cold idle issues? I have to give some throttle until warm. Idles OK avter a couple minutes. Does that mean my WUR needs an adjustment or a reebuild? Or anything else I should try first?

Warm controll is whithin spec. Which means my high consumption and popping from unburnt fuel in the exhaust is another issue. Would changing my injectors be a good place to start? I have no idea how old they are or how they are functioning.

Any other advice for a ever learning air cooled newbie, from the results from my testing?
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1977 911s

Last edited by AndreasK; 06-02-2024 at 10:05 AM..
Old 06-02-2024, 07:53 AM
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