Good people of GRM, please bestow your wisdom.
On my 320i 2.0, w/9.5:1, header, and 32/36, looks like my jetting is ok from a quick plug read (nice and tan/brown from the #1 cylinder - not checked the rest yet). Primary idle jet is apparently still too small with a 65, since I need about 3 turns to get it to idle nicely. 140 Main, 165 secondary.
I get a stumble at off idle and then from part throttle to WOT.
Do I need bigger on the idle jet (and nobody seems to go bigger than 60)? I got less of a stumble when I had a 150 main, and I could get it to idle with about 2 turns on the mixture screw. But, I had a little bit of soot coming out the tail pipe with that combo.
What sayeth ye?
Are the 2 bores linked sequentially or simultaneously? When I got the simultaneous opening linkage for the 32/36 on my built 1275 Sprite it ran better and stronger.
I'd go up a bit bigger on the pilot and see what it looks like.
When all else fails - call Mike Pearce @ Pearce Manifolds and do what he says - no kidding.
On 32/36's if the idle screw is not in the specified range it'll do that, it's some sort of Weber weirdness due to the fact that the 'idle circuit' is actually the 'low speed' circuit. It also has an idle circuit on the secondary, sort of a cheapskate's accelerator pump, so be sure it's clear and the idle stop is properly adjusted. The secondary adjustment is: .002 from the throttle plate to the venturi wall. Typically this doesn't need to be adjusted unless the carb has been monkeyed with or the linkage gets bent, worn etc
http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm
Also, be real sure the ignition base timing is correct, the vac advance (if used) is connected to correct vacuum (does it use ported or manifold vacuum?) and that there are no vacuum leaks. A vacuum leak will screw jetting up so bad it ain't funny. When checking for vac leaks, don't forget to check the brake booster.
02Pilot
HalfDork
10/14/12 8:28 a.m.
FYI, there is a ton of info on the 32/36 on that motor over on the 2002FAQ board.
Linkage is sequential. There are no vacuum leaks (plugged many as I got it up and running). I'm not sure I have any issues with throttle stop, but I could/will check it. And, stumbles no matter where my idle screw is (and just causes my idle to be in the 12-1500 range with no change in driveability).
I think at this point I'll try a bigger primrary idle jet, even though NOBODY on the 2002FAQ board (at least that ever replied) has done so, even with my set up.
I'd have to double check the vacuum advance as being port or manifold, but if memory serves, the original injected set up ran off of the TB, not the manifold. I'll check that as well.
Looks like a call to Mike will be in order.
