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Two Tone Two Tone is offline
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Join Date: Mar 2006
Location: Nova Scotia, Canada
Posts: 44
Thanks for the reply Souk, I understand about being busy at work!

I tried the field method this morning after my drive in (40 minutes - so thoroughly warmed up).

Car at idle - 1000 RPM

Pulling down on the air plate yielded an immediate drop in rpm. The further down I went the slower it got. I didn't take it to a stall. Actual distance I moved the plate was very small.

Pushing up yielded an immediate increase in rpm. Continuing up resulted in more RPM up to about 2000 - 2500 (couldn't see the tach) then it would begin to die. Again, very little actual movement.

I read on Jim Williams primer that a slight increase followed by roughness while pushing up is likely about right. This would be more than what I would call a slight increase. Does this sound like its close enough for now and I should get on with fixing the cold start and idle problems or does it sound a bit lean based on the above?

So, assuming adjustment is warranted, if I now richen the mixture screw, Idle should increase but the mixture will be closer to where it should be. I should then adjust the bypass screw to bring the idle back down and then try the 'lift test' again, and so on. How am I doing?

Will do re. cleaning WUR and AAR and pressure testing. I will definitely report back.

Thanks again, much appreciated.
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1977 911S with a 78 SC Engine

Last edited by Two Tone; 05-09-2007 at 08:13 AM..
Old 05-09-2007, 08:10 AM
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