hey,new guy here i recently bought a 90 b2200 2.2 2brl a/t i took it thru emmissions and failed big time i noticed when i bought truck that the secondary air hose assy has been cut from the exhaust manifold and crimped.is that really that important to have to pass???i also notice that it idles at around 1100 or 1200 rpms.any suggestions? thanks

 

Idle it back down to about 800rpm, that will help some. Make sure you're engine is running up to temperature. If it's running too cold, it won't burn all the emissions. Also, put in new plugs and make sure the iginition is firing as hot as it should be. Adjust your carb if you need to lean it out some to make sure all the fuel is burning. If it's too rich, you'll have alot of junk left in the emissions. Don't attempt this step if you don't know what you're doing.
After that, make sure the air pump is hooked up and operating. Air pumps are really just a farce. They pump extra air into the exhaust to dilute the pollutants coming out. It doesn't actually cut down on what's coming out. Did someone punch out your converter that owned it beofer you? If that hose is crimped, I'm going to say there's a decent chance they did. Otherwise, there's no real advantage to doing what they did.
If you have a punched cat, you're going to have to replace it to pass emissions. That's about all I can offer up. After that, you're going to have to go to a shop to have them check it out. You could replace the EGR and PCV valves, but you're just taking shots in the dark on those. I don't know how to troubleshoot them.

 

I use to tweak my 4brl to get it by inspection. Do all of the above^^^^. Locate the idle jet screw on the carb. On the 4 their in the front at the bottom, not sure about a 2. Start it up, start turning the jet screw in ( clock wise). As you turn it in, at some point it's going to start idling ruff. That's good, your running lean. Lean it out as much as you can without the engine dying. As the rpms drop off, turn your idle up. Get it inspected, even though it's running like crap it will pass. Once your out of the station, turn your jet back open until it starts running smooth again and back off on your idle.

 

That's a good description that goes into a little more detail. Depending on how bad you failed depends on how far you have to go to get it to pass.

 

You don't have to cheat. Change the
catalytic converter(s) and the o2 sensor.
It will not only pass like a new truck but
also keep the air we breath clean.


Nick

 

Yes, do a full tune up if you havn't done so already.

I would not touch the idle, it is idleing fast because something is not working right. Playing with the settings on the carb will only screw things up worse.

The manual adjustments on the carb control IDLE mixture, speed, and fast idle speed, leaning out these settings will only make a difference at idle, off idle you will still have all your same emissions problems if you don't fix the actual problem.

The 86-93 B2000 and B2200 carbureted models do not have an air pump, they have a Pulse AIR injection (PAIR) system which uses pulses from the exhaust and one way reed valves (located on the air breather) to pull fresh air into the cats.

Catalytic coverters reach extremely high temperatures to oxidize the pollutants and break down NOx emissions back into N2. This means they require fresh O2 from the atmosphere in order to work efficiently. The most harmful emissions are measured in Parts Per Million, dilluting them with a little fresh air isn't going to change the reading a whole lot if at all, its like drinking a crap load of water or any other myth to pass a drug test, it doesn't work that way not to mention dilluting the emissions in the exhaust pipe is no different then dilluting them in the open air.


Again the pair injection system simply pulls in fresh air into the cats, other than some unpretty clutter in the engine compartment it can cause no power losses or gains if all is working properly.

Yes, without the cat you'll never get your emissions low enough. If any shop is doing their emissions test by the book it would fail as soon as they opened the hood since all emission inpsection levels require a visual inspection of the emission devices, if they are not present, damaged, or nonfuctional and they find it the vehicle will automatically fail.