Another Emmisions Question

[tucson fj60]

Sorry, but yes another emmissions question. I've searched through other postings, but didn't find any thing that I thought would help me out.

I rebuilt my carb, replaced the wires, plugs, cap, rotor, air filter, made sure the emmissions hoses are good and properly connected and this improved my test results, but it still failed the under load CO pass Ariz emmissions.

Any suggestions, better tune the carb, a bad cat, etc.??????

Thanks in advance, JT

 

[swank60]

Here are the areas I would check:
Replace the PCV, do a by-the-book test of your air injection system, check your timing and check your float level in the rebuilt carb. Also, there's a vac manifold in front of the carb on the intake manifold with three nipples on it. Pull that out and soak it in b12 and blow it out. If that gets clogged, your air injection system won't put air where it needs it.

You can check your cat by getting up under the truck and shaking it. If it sounds like it's full of little rocks, it's bad. If it doesn't, you should be okay unless you burn a lot of oil - if you burn a lot of oil, it coats the beads and they don't catalyze the way they should.

 

[60wag]

The stock 60 cat is a pellet type and can rattle if its good or bad. The test for cat function is to check for a temp rise across the cat when the engine is running rich. If its the original cat, it is likely weak if functioning at all. Many 60's can pass emit tests with weak cats if everything else is working correctly. I'm with swank60 on testing the ENTIRE air injection system. The Toyota emissions book has a step by step walk through. If the AI system is ok, make sure the vacuum switch and evap recovery system is fully functional. I have found defective components in both these areas that lead to high CO readings.

 

[swank60]

60wag - how do you do the temp testing on the cat? Thanks for the additional info though - the emissons book doens't go too much into it and I've only had a few conversations with others about it...