Hi all,

I finally got the monty running (tranny swap). I took it to have emission done, and it failed. This is in WA. Here are the numbers:

cruiser:
HC - limit (150) - result (196)
CO - limit (1%) - result (4.27%)

idle:
HC - limit (220) - result (568)
CO - limit (1.2%) - result (1.46%)

I don't know how long the PO parked this truck. Here is what I've done so far before the test:

1. new spark plugs and wires (NGK)
2. new cap and rotor
3. new air filter
4. new fuel filter
5. new belts
6. new t-stat
7. fresh oil
8. new O2
9. fresh coolant
10. new PCV

The only thing I put in was the fuel additive (cleaner) from shell. The V power stuff. I filled up the tank with Chevron and drove to half tank before going in for the test. Could the fuel additive be the problem? What do I need to fix? Idle is around 600 rpm. Thanks.

Can't keep track of what everybody's truck is. Could you put it in your profile? Have to know if fi or carb to even start to help...

What is wrong with you Eddy? Old age must be creeping in. <img src="/forums/images/graemlins/smile.gif" alt="" />

Sorry.

1986 Carb.

My $ is on a leaking float bowl needle or float set too high. Take off the air cleaner with the choke open and look for signs of fuel dripping onto the throttle plates.

And yes, I'm getting older. And crankier...

You might be able to reset the idle mixture to get into compliance at idle, it's best to do so while it's connected to the emissions analyzer so you can see the results. If it can't, suspect the cat-converter/s if all else checks out OK. 1% to 1.5% CO is pretty normal if the cat converter/s are hollow.

Make sure that the choke is opening fully when the engine is hot.

Make sure that the upper exhaust manifold is not cracked, the O2 sensor will see the extra O2 from the air being drawn in and send a lean signal to the ECM which will richen the mixture.

Ok, I checked and adjusted the timing to about 5 or 6 degree BTDC. Idle is now at ~750 rpm.

Sorry for being dumb, but not sure where the choke and float bowl is? Any picture? I'll try to take pic and post so that I will understand.

Keep it coming. Need to get this thing pass emission. Thanks.

Choke is the flap on top of the carb that closes the throat to raise manifold vac and cause the carb to run richer (which will lead to higher CO on an analyzer) so the mixture is rich enough for cold running. From a cold engine, remove the air cleaner and move the gas pedal to the floor once. The choke flap will shut. crank the engine and let it idle to full warm and blip the throttle once. The flap should open straight up if it's not already. Now use a flashlight and look down the carb barrel. See any fuel droplets vaporizing on the throttle plate at the bottom of the carb? Should look like instantly disappearing dark spots.

Here's what I did before reading your post.

I looked at the throttle body when cold. The flap is closed. I ran the engine until hot and it is opening about half way. I then ran some carb cleaner in there and the flap is now fully open. I haven't look down with a flashlight yet. I don't know if I could still see droplet after running carb cleaner in there.

Here are some pics.

[img]http://picasaweb.google.com/lh/photo/g9LyRXo-XRmmB9_PabM6PA?feat=directlink[/img]

carb1

[img]http://picasaweb.google.com/lh/photo/MRZ_erb5earnvfia8rRzng?feat=directlink[/img]

carb2

Sounded like the engine is a tad smoother now.

What else do I need to do to get the HC and CO down?

Lor,

In order for those picture links to show up as an image, it has to end in a .jpg or .gif or some other image file. If you look at your links it ends in a "directlink" which the forum software knows is not an actual image so it ignores the link. <img src="/forums/images/graemlins/kewl.gif" alt="" />

With Picasa, I'm not sure how you can get the actual image link versus a pointer like what you have in your post.

Glad you simply posted the links though. <img src="/forums/images/graemlins/cheers.gif" alt="" />