cant pass smog

[bryant2482]

hey guys ive taken my 720 to get smogged 3 times in the last week. i changed all my plugs, exhaust ignition coil, rebuilt and cleaned the weber 32/36, added seafoam, 100 octaine and "gaurenteed to pass smog" bullshit in it and advanced the timing. what else is going on cuz i passed last year with the weber.

 

heres my recent results

 

idle speed co 4.49% greater than 1.20%

high speed co 1.79% greater than 1.20%

idle speed hc 627 greater than 220 parts per million

[Z-train]

Change the oil,change the airfilter,clean PVC,RETARD timing.

[bryant2482]

ok cool thanks

[flatcat19]

Running super rich.

[bryant2482]

are you saying i should run it rich? or its already running too rich?

[sreams]

HC = Hydrocarbons = unburned fuel. When HC is high (yours is), you are running rich. You should lean out the carb.

[Z-train]

However,dirty oil,plugged filters & in-op PVC can contribute to high HCs.So make sure all else is right before diddling with the carb.

[bryant2482]

i have leaned out the carb as much as i can before the motor start to idle rough and jumps around. is it possible that the stock catalytic converter could be going bad?

[Z-train]

It is a possiblity.....

[bryant2482]

finally passed! just had to re-route some vacuum lines

[Z-train]

Get a FSM and make sure they are where they belong.

[dato]

Haha when i was a little kid my dad would go in with his 720 and tune the carb

so it would be idling really low around 500 or so and take a little steel wool and shove it up the exaust

passed every time. lol

[az_rat210]

You can add isopropyl alchohol to the gas to pass emissions. But make sure you have some spare fuel filters as it will clean out the gas tank.

[Rays74]

/\/\/\ I've seen this advised before, be cautious with this though since a carburetor can't compensate for different fuel make ups like FI can.........you can get the mixture biased so the engine runs rougher than on just gasoline alone. I tried this on a late 70's Jimmy truck before and it seemed to make things no better.

 

--Ray

[I'm BLUE]

finally passed! just had to re-route some vacuum lines

 

good news ! :)