emissions help

[desertbronc]

i am having trouble passing emissions, the part i need to pass is the carbon monoxide under a load (on the rollers) the maximum is like 1.20% and on the first run i ran a 2.42%, i added some sea foam to my tank to clean out the fuel system and then the truck ran a 4.20% ***??? the carbon monoxide idle test is fine and the hydrocarbons idle and loaded are fine. is there any tips on what to do to lower the carbon monoxide while running. i live in AZ by the way

 

[Seabronc]

The addition of Seafoam was most likely the cause of the increased carbon monoxide. You would have to run enough gas through the engine to clear most of that out of your fuel mixture. Once you put an additive into the gas tank that is in the recommended strength it take 3 to 4 fillups to completely clear it from the tank. Not that Seafoam is a bad thing to do once in a while to clean up the internals an upper intake components.

High carbon monoxide is the result of not completely burning the fuel which is usually a result of running too rich. If it is a Holley, their basic design is to run a little rich. Do you have an original intake system? If a carburated engine, how old is the carburetor and do you have all of the original pollution controls installed?

Good luck,

>-

 

[Seabronc]

I forgot to mention one other possible reason for the fuel mixture not completely burning. That is,a weak ignition spark. Check the condition of the spark, you should have a good clear blue arc. You can get a tester that lets you see the arc or pull the boot back and hold the spark plug end of the wire close to the block. If it does not appear to be a good strong arc, don't automatically run out and replace the ignition components. First check the battery to engine block and frame ground connections. Clean them up and check the condition of the (-) cable ends.

Good luck,

>-

 

[desertbronc]

its a edelbroc carb and edelbrock intake manifold, i am most definately trying to finish whatever is in the tank. yes i just replaced the air pump and everything else is still attatched egr, cat etc... i will check the spark tomorrow the plugs are about 2 to 3 years old. there is no way to lean out the edelbrock carbs?? i also hears about putting a bit of alcohol in the tank, they said it would help.

 

[miesk5]

yo

I just lost a lot of typing here, again...

I know Fred has a mucho better handle on this that I, so all I can do is pass you on to:

Recarbo

Look @ various sections incl;

Smog Trouble-Shooting Chart The complete chart of smog problems.

FOR EXAMPLE:TEST SPEED, CO, HC, SYMPTOMS, POSSIBLE CAUSES,

CRUISE (2500RPM) Dyno: 60mph @ 30hp. CO HIGH, HC NORMAL;

Exhaust smells rich when throttle is held at a steady cruise speed (2500 rpm).

Float level a little too high.

Main jet a little too big (possible but least likely. Check all other items first.)

A little dirt or gum partly blocking the main air bleed.

Power valve leaking a little.

TPS out of adjustment.

...................

See more there

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Edelbrock CARBURETOR FREQUENTLY ASKED QUESTIONS: How can I lean down my carburetor to get better mileage?

A: First off, make sure the correct size, (cfm) carburetor is installed on the engine and be sure the idle mixture screws are properly adjusted (see page 6 of the Owner's Manual). You can always make your carburetor leaner, but this will not always improve gas mileage. Since every engine is different, there is no way of knowing how much of an affect leaning down the carburetor will have on your engine. You can refer to your carburetor owners manual (download here) and the calibration chart inside to lean down the carb. Start off light, but keep an eye on the plugs to make sure you aren’t taking it too lean. You will see on the chart that you can lean the carburetor down in different percentages in different modes, cruise and power.

..etc.

See pages 6, 11 & 12, etc of that Manual which is 1.83 MB pdf