I'm allowed 3% CO at idle, and I scored 6.53 last time.

I adjusted my timming, did my plugs, changed the FILTHY SMALL aircleaner, and fan with a 1/2 tank of Premium, and got her good and hot...

This time I blew 3.47. I have a good feeling the idiots who owned the truck before me (hence the tiny airfilter) played with the carb (they admited to "tunning" it)

What can I do to try and bring my CO down?

 

You could try leaning out the idle mixture slightly. BTW, use the lowest octane fuel you can get away with. Running premium will actually increase emissions if the engine doesn't require premium.

 

What is your NOX reading at idle?
If you're running too rich, your NOX will be a very good number. Leaning it out decreases HC and CO but raises NOX. Once yiu pass about 15:1 NOX emisions go up like a rocket.

 

Check your PCV valve as well. If it's clogged, or partly clogged, that will cause your CO to go up.

 

If you lean it out too far and blow the NOX number, running a tank of half 87 octane/half E85 will reduce your NOX reading.

 

Good tip!

 

Ok guys, any of you know what this does?



Or see anything else out of the ordinary?

 

I can't tell where that hose is routed, but I'm more interested in the one the arrow points to in this pic...



Does that go to the valve cover?

Do you have a PCV valve hooked up properly?

 

The hose you pointed out I went to look at, it goes here:



It hooks into my exhaust manifolds on both sides.
I take it this is my EGR?

And this:



The kinked hose just loops back around into that black round thing by my EGR. Is that EGR related? I'm gonna have to scrounge through junkyards for a stock airbox....

 

Your EGR valve is behind the carb. The rest of the hoses/tubing going to your mexhaust manifolds are part of the thermactor system. Do you have your smog pump hooked up???

 

I have no smog pump. I was under the impression I didn't have one from the factory. My moms mechanics had a look at the truck, and they told me it was "Commercial/Heavy Duty" and that I was lucky because I didn't need one. I guess I just believed them because I don't have a cat either...

So is this really for a smog pump? Does anyone else have any pictures of a 460 w/ smog, I don't even know where it might go on my engine, I don't have any available pulleys.....

Thanks....

 

You see those metal tubes that go down by the spark plugs, and into the exhaust? That's one of the two places where the air from the smog pump goes. The other is to the cat. That thing in the back with the hoses and pipes going to it is the air control valve. It uses manifold vacuum from two different sources to decide where the air from the smog pump goes.


What is the red arrow pointing at the picture below? It's hard to tell, but it looks like a smog pump, with the output hose the one with the green arrow. If I'm mistaken, what are they?

 

Red arrow is my alternator

I certainly do not have a smog pump. Its possible that I might have had one once, (though I don't have any free pulleys) but its not there now.

I believe the green arrow is just a water hose that goes into (IIRC) the head.

FWIW, I do pass the "underhod" inspection when I smog it...

Thanks

 

Ahhhh, I see. The way it looked in the picture, it could have been a smog pump with the hose going somewhere else.

I can tell you this much with certainty: Those exhaust manifolds, and all those hoses and metal tubes are only used with a smog pump. Your EGR gets it's exhaust from a passage that goes underneath the intake manifold.

That engine had a smog pump, and there is no way you would pass the visual out here. It must be much more lenient where you're at.

 

All right, all right, guess I'll find a smog pump.

Any idea where I can find a diagram for this? I can find and mount a pump, but I'm sure I'm missing some other parts here and there....

Wonder if I can lower my CO enough to get past the emissions as is. Only need to knock another .47% down.

I was planning to do some long tube headers and ne exhaust, so if I can pass emissions without a smog pump, I'll gut the rest of the system....