Thank you all so much, I’ll make sure to check out some threads on colorado emissions.
The local TLCA club has their own forum -
Rising Sun. That being said, I'm in Denver daily driving a 60, and here's some thoughts (that I post on every single "help, I can't pass emissions!" thread)...
There are three very key things.
1. Baseline that motor: replace the air filter and spark plugs (maybe the spark plug wires too), set the timing properly, set the valves properly, do the "lean drop" carb tuning method, and change the engine oil and filter. I see you have the magical discontinued special oil filter on your motor, so if that's recently been put on keep it. If it's old, take it off, drain the oil, and put it on the shelf because it's kind of a cool historical thing you can't get anymore. All the procedures for baselining can be found here:
https://forum.ih8mud.com/resources/2f-engine-repair-fsm-1991-printing.91/ For a 1983 FJ60, I prefer the 1980 printing of that manual, but I can't find the PDF right now. This 1991 printing will be fine.
2. The Emissions Factory Service Manual, available in PDF form for free here:
https://forum.ih8mud.com/resources/2f-engine-emission-control-1981-36043e.138/
3. This graph below. It's never failed to accurately explain why somebody failed. It's been right every time I've used it or suggested it to other people.
Do the baseline stuff as described.
These trucks need almost
every component in the emissions system to work properly to pass stringent IM240 (roller) smog testing like we have on the Front Range. The Emissions FSM will details test procedures for every single widget under the hood. You'll look at the manual then look at your engine bay and say "I ain't doing all that! It's way to much! I read somewhere that I can just put some e85 fuel in and it'll be guaranteed to pass!" You need to do it anyway. After you do and after you get everything working, the long term health of your motor and future ability to pass emissions testing will thank you. Don't put band aids on problems because you'll just chase your tail down the road. Plus the Emissions manual spells it all out for you. It's the world's best and easiest cheat sheet for these trucks. Why venture off into the unknown with undocumented hacks? Sometimes those hacks have their place, but it's not as a bandaid for untested emissions equipment.
After you get all of that stuff working, run through the emissions testing center again. Compare your results to that graph I posted above. See if you're running rich or lean. Then compare that to the systems in the Emissions FSM. Think about what those systems are doing. Smog pump leans the mixture out during certain times. EGR actually richens the mixture at certain times. Etc, etc. If you're running rich try to pinpoint why. Same if you're running lean. Remember that the tuning you can do on the carb only affects the idle. These trucks
will pass emissions with stock jets, so don't get carried away with that. That's sort of a "I've exhausted all opportunities" thing.
There are some other finer-grain things beyond this, and yes some hacks. Do the above three first. You may end up needing a carb rebuild, but figure out the other stuff first and try to get it to pass.
And come to a Rising Sun meeting some time - first Wednesday of the month. We need more 60s!
