AFR

JFENG

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Bavbob stopped by this AM so we could check his Weber 32/36 DGAV setup.

We did a quick visual check, and the only questionable thing that we found was the cold air flap in the air cleaner housing, (which didn’t seem to be opening). We heated it up with a heat gun to about 150F but the ‘bulb’ didn’t move the flap at all. BavBob could move the flap easily by hand so I need to check the manual to see if we had gotten it hot enough.

This is the first automatic classic BMW I’ve ever worked. BavBob started it up and it idled at about 1000-1100 in Park. That seemed too high to us for adjusting idle mixture (eg throttle plates were probably open a bit), so we dropped rpm to about 700rpm. Next I went in and out on the idle screws to see where we were in the adjustment range. I personally think a carb adjusting tool makes this job vastly easier than a plain straight screwdriver


Anyway, there was a huge range in the idle mixture screws between too rich and too lean, at least three turns. Maybe the throttle plates were still slightly cracked open? Anyway, I set it at 1/2 turn out from too lean on both carbs and then we raised the idle rpm up to just under 1000 so the idle would be strong in “D”

On the test drive the AFR stayed in the 13.5 range when cruising, and 12.8 at WOT. Car drove really well, and the automatic behaved very nicely. I do not think the good driving nature of these cars is compromised by the automatic transmission. Sure, it’s not as fast in acceleration, but otherwise I can see why some folks like the auto-box. This was the easiest/fastest carb tune up I’ve ever done, and I guess that’s why the Weber conversion is so popular.


I suppose we should have had the Blue Book out for the official procedure and settings.

Wish I could get my 38/38 number this good.
 

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JFENG

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I would thank John personally on this forum but am in fear of another "bromance" comment.
I’m always delighted to help out a fellow E9’er, especially those who take on the challenge of E9 restoration by their own hand.

Some of you guys have pretty nice garage setups, lifts, tools galore, and you do amazing work in your shop. What impresses me is BavBob did a full bare shell restoration in a small, dimly lit garage with a cracked slab, bikes and other stuff everywhere, limited tools, no lift, no air tools, no tig welder, no parts washer and media blaster, and did you guys know he only has one arm?

Inspiring.
;-)
 
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Stevehose

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Those are good numbers, typically the idle mix is the last adjustment because throttle plate adjustment will throw off ideal mixture settings.
 

JFENG

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Maybe I’m doing it backwards, but I’ve always done the idle circuit first, because it’s the only carb circuit which (theoretically) operates in isolation ( at idle). Once off idle, multiple circuits interact, and it gets complicated. By doing idle jet and setting first, it reduces the complexity of what to tweak in progression and main circuit operation.


But I agree 100%, Steve, that tweaking the idle circuit may still be needed while dialing the progression and main circuits.?

John
 
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Mot27cars

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I’m always delighted to help out a fellow E9’er, especially those who take on the challenge of E9 restoration by their own hand.

Some of you guys have pretty nice garage setups, lifts, tools galore, and you do amazing work in your shop. What impresses me is BavBob did a full bare shell restoration in a small, dimly lit garage with a cracked slab, bikes and other stuff everywhere, limited tools, no lift, no air tools, no tig welder, no parts washer and media blaster, and did you guys know he only has one arm?

Inspiring.
;-)
Aweome
 
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