Vang530

cold start fast idle revs up to 2k rpms or so...this is when the cat turns red and its runs rich and you can hear a very mellow backfire in the exhaust. my best guess is that its dumping too much fuel and runs rich on cold fast idle. spark plugs were a slightly bit more black then I'd like. I have to let it warm up until the fast idle turns off, then turn engine off and on again, after that it runs good and nothing wrong.
when engine finally warms up if I don't turn off and on engine again after fast idle turns off, it runs way rough and I have to adjust mixture screw to get it smooth (running too lean after the rich fast idle)..causing my manifold to get hot. Again, if i turn the engine off and on after the cold fast idle it doesn't happen and runs ok.

short version:
runs rich on cold fast idle and cat gets red hot
after cold fast idle goes away runs lean and rough and manifold get hots
no problem if i turn engine off and on after cold fast idle goes away

running a weber 32/36 with smog legal water choke
new points, new spark plugs, all new vacuum hoses
timed to spec
haven't touched jets, tried to tune mixture screw following redline instructions (2 screws out and adjust from there) etc..
everything else stock...passed smog few weeks ago with very clean numbers.

TIA

gillesdetrail

iTrader: (1)

You might have a clogged catalyser, I don't think running rich would make the exhaust hotter, I think it would be the oposite.

INFINITY

also a for to drop the pressure from the pump will help the carb. also what is your timing set to

Vang530

it looks like my octane adjuster plastic knob thing doesn't go up and down so i'm guessing vacuum advance shot?.