cis co reading question...

[rcwaldo]

Hello all,

In trying to overcome my off idle stumble, pop, bog then run ok after 3000 rpm problem, Ive found to what I think is a very lean condition. About 2000 rpm my meter shows .6 to .9%co.

I have adjusted the idle co to about 2%co (per text) and it runs really lean off idle.

My question is there a way too adjust mixture for mid range? What would cause a midrange lean condition. Does anyone know what is optimal CO% for off idle (2500-3500rpm)?

My fuel pressure testing set-up that I ordered last week is not here yet. I am sure I will find out more once I test the control pressure circuit.

The car is a 74 911 2.7 BTW. Less than a mile on a total rebuild.

Thanks guys,

Chris

[stormcrow]

Wait until your pressure gauge arrives, then you can really see what's going on. Gotta have the right tool to do the right job.

Steve

[azasadny]

What ever happened on this? What was causing the >3000rpm stumble? I'm having the same problem and have a Gunson on the way to test CO levels.

[greg bradbury]

Sounds to me like the air flow paddle is getting fouled on something or is binding. This could cause leanness off idle

[kach22i]

From what I understand it's far more common of a problem running too rich at idle.

I'll be interested in reading what you find out about this running too lean at idle (below 2,000 rpm).