failed for high CO in northern CO (1 Viewer)

[forestdan7]

Took my 85 FJ60 in for its first ever emissions test today, as they're bringing testing back for the northern Colorado front range. Passed everything but CO, which was 81 (limit is 45).

Their info sheet said this could mean it's running rich. I'm no carb expert, but it looks like I may have to tackle an adjustment.

It could probably use a tune-up too, but the last one is only about 45000 miles old, and it's running really strong. Back then, new plugs, wires, cap, rotor, PCV valve, K&N air filter cleaned, valves adjusted, timing checked.

Thing is, I'm broke right now, and need this thing to pass quickly and cheaply. And I'm not up for running E85, or dumping in a quart of denatured alcohol. (See, I did search!)

Could the K&N be screwing things up? I've been thinking of scrapping it anyway, and going with a Toyota paper filter at the next tune-up. Anybody think I could just switch to a new air filter and get it to pass?

Any advice appreciated.

 

[nuclearlemon]

i've managed to get through emissions every year in all my rigs with two bottles of heet in a half tank of fuel (basically alcohol) and run it hard for a good hour on the highway before you go.

with it having miles on the last tuneup, do that too. check plugs, change oil throw a new filter on. oh, and have a new gas cap just in case. if you pass with flying colors and then fail on the gas cap, there's no doubt you'll fail when you go back. don't install the cap, just have it. if they say it fails, hand em the new one.

 

[cruiserfj45]

A good carb adjustment, valve adjustment and spark plugs may get you by. And ditch that K&crap air filter.

 

[forestdan7]

Good advice, thanks. Yeah, been wanting to get rid of the K&N gimmick for a while. Think I'll try to find a stock 2F air filter at a dealer today, put some Heet in it and run it for a while, then try again. Might as well while I've got the 10 days for a free re-test. If it fails again, I'll suck it up and order the tune-up parts and do it right.

 

[2mbb]

45000(!) or 4500 on the last tune up. Recommended maintenance intervals for valve adjustment is 15000 and spark plugs is 30000.

What is the Colorado test? Idle or at speed or on a dyno? Also post up the other numbers from the test.

Running rich (eg unburned fuel) could also show up as high HC. CO is also reduced by the catalytic converter, which also requires proper operation of the AI system.

 

[toolman]

In addition to checking all the things already posted, my money is on the air pump. Make sure it's working correctly and actually getting air into the exhaust manifold. If it's putting out enough air (not sure of the spec here) it may not be making it through the valving (is that a word?) into the manifold.
I have mine directly routed from the air pump to the manifold and it's passed emmisions a few months back registering only about half of what the limits were. I live in Wellington, CO.

 

[forestdan7]

I know, 45000 is a long interval. But it's been running great, getting good mileage, no excess valve chatter.. Guess the old girl is getting back at me for not spending time with her.

The Colorado test is on a dyno, varying speeds up to 60 mph. First test, my HC was right under 6, and 6 is the limit. CO was 81, with 45 the limit. Forget what NOx was, but I passed that easily.

Yesterday I ditched the K&N, put in a new Toyota air filter, filled a half tank with 91 octane and one bottle of Heet, ran it on the interstate for nearly an hour, and went back in for the free retest. This time I failed HC (6.015, limit 6) and CO (94, limit 45), and passed NOx (2.8, limit 12).

So I'll do a full tuneup, and run through the emissions manual while I'm at it. I hope the air pump is working okay. Last time I had it off, I could feel it pushing air when I spun it by hand. May not be enough, though.

Thanks for all the input.