My corona 20R passes the 2500 rpm and HC PPM emissions check but fails the idle.

I adjusted the mixture screw, turning it in more lowered the idle and made it pass the 2500 where it was failing before, but the idle is still up at 530ppm where it needs to be down below 400.

Any ideas? Would adjusting the distributor timing or valve clearance possibly help?

Side issue. I had to disconnect the smog pump belt because the bearings went out, and they are failing it also due to equipment check, so have to buy a new one and hook it up again. Could this also help my idle emissions failure?

thanks
josh

 

I was having a similar problem. what
i did was turned my idle down to 890-900
(was 1070ish when i failed) advanced the timing 2* stock is 8*so 10*
turned the mixture screw till it almost didnt run
my vavle clerance was alittle loose but not much
Then, hears what suprised me, I put a bottle of this RxP gas kicker
stuff in my gas drove around for awhile got it good and hot went to the smog check station and passed with flying colars. Even the guy who tested it was suprised it passed.
well, that just what I did and it seemed work. GOOD LUCK to ya.


Oh as far as the smog pump goes, mine was working fine so no help to you there. hope you get her figured out.

 

just noticed your in colorado. depending on what altitude your at, you might need the get differant jets for your carb!

 

Retarding the ignition helps immensely. The more the better. I've passed dialed so far back the car was barely drivable. You will have to open the throttle to bring the idle back up (idle speed adjustment screw) and be careful that the motor doesn't overheat.