Ottoman5000

iTrader: (1)

Car starts and runs. Driveable. Stutters at parts throttle till fully warmed up. Full throttle, pulls hard.

failing emissions bad. Installed new cat. Smells super rich now matter where I tune it too. Timing is spot on. Carb seems to be the next issue.

fuel level is slightly above half way in front fuel bowl. I’m going to rebuild the carb. Should I install new floats while I’m at?

what else should I do while it’s out? I have the hydrate kit

klptk

iTrader: (1)

Did you check that the airpump is working and actually sending air to the exhaust? You can reroute the vacuum lines so it constantly flows to the exhaust ports.
My -SE recently failed and got gross polluter (like five times over max) with everything running good and a brand new cat, turned out the ACV was dumping air out the relief. Fixing that took my emissions down to almost zeros across the board.

t_g_farrell

iTrader: (1)

Don't touch the floats unless something is not right. Do not use the new seats and needles unless the old ones are really bad. If you use the new ones, you will need to burnish the corners so they don't stick. What year and model is this? I'm assuming FB 12A for now. SE is a completely different animal and has no carb on it.

j9fd3s

iTrader: (3)

+1 on the ACV, if its not working, you will never pass smog

Ottoman5000

iTrader: (1)

It’s a 12a. So just trying switching the vacuum lines on the acv? I’ll try that tomorrow here. Won’t that make the cat to hot though?

Benjamin4456

That's honestly exactly how I passed smog. I had about half a cat, an emissions system that wasn't correct for the engine/exhaust combo and all, and I managed to pass by 1ppm (passing here is 220ppm on HC's). That was also me having only known rotary's for seven or so months and therefore not really knowing how everything worked.

So anyway, this is how I passed (albeit this is not optimal, but might work for you). First, you need to well understand how the smog system on your car works, as they are all slightly different, but here's what I did on my SA: force the air pump route to port air via supplying vacuum to the correct line (it should already be that way, but with failing equipment it might not), enable vac advance at idle by jumping it to an idle vacuum source (this makes the car unhappy, but it does sometimes clean up the tailpipe a bit), and finally if it's an SA, force the trailing ignition to be enabled when above-idle if you have an aftermarket exhaust [EDIT: I believe I was wrong the first time I wrote this; trailing is active at idle but deactivates right above it. The SA's had a tps (s = switch) as opposed to the FB tps (s = sensor) and it only told the car when it was above idle, that's why many smog systems on the SA are based around either the idle or the two switches on the trans]. This is done by unplugging the two prong plastic connecter that comes out of the ignition box. [EDIT: the trailing ignition part just mentioned is for the cars with the early electronic dizzy (as in the 1980 model) where the control box was mounted on the strut tower and the ignitors were not on the dizzy. The reason this is an issue is because by default, SA's (I'm not sure about the 79's points system) disable trailing ignition in a bunch of cases to keep the thermal reactor up to temp. Off-idle is one of these cases. If you no longer have the thermal reactor, you are better off disabling this feature as you'll run cleaner with both sets of plugs going. The thermal reactor needed the richer mixture/unburnt fuel to stay warm enough to do its job, a cat does not need this. This feature is a large part of the reason I failed worse at the 2k rpm test than at idle (after I ditched the reactor) - the 'smog' part of my ignition was shutting down above idle.]

Now that's not the right way to pass, and really I would only do those things if your car is in a 'messy' state (for example, mine came from 16 years in a field and I was just trying to get road legal, not to mention that the po did a whole bunch of weird stuff). Another thing to keep in mind is that different states/counties/countries have their own regulations too. Here in Oregon we only do an idle tailpipe test (no visual besides a quick under vehicle glace). If you fail that they let you test under no load at 2k rpm, and if you fail that you're out.

The ACV's internals can also get messed up and cause issues. The diaphragms can dry out and crack, meaning they won't hold vacuum (this can also cause a vacuum leak) which is what happened on my car. I sealed it jankely (read temporarily) and it worked well enough to pass. The valves in there can also seize up, again making the air go where it shouldn't be. The ACV has two main air routes: port-air and split-air. Port-air runs to a 'port' in the center iron that connects to each exhaust port through internal passages. It is what should be getting air under most cases when driving around/idling. When warming up the air will usually be routed to split-air, which is the cat's 3+1 supply. I don't fully understand all the cases when the ACV/ECU decides to route air various places, but that's my general idea. Essentially, during a smog test you want air going to port air, that's it.

Enabling vac advance at idle is just an easy way to advance the timing (don't drive like this, please). Alternatively you can also just turn the dizzy a little bit and then turn it back when you're done. The way I did my smog test(s) is I arrived at the facility, pulled over, swapped all my 'tricks' on and then tested. If I failed I'd pull around, change a couple things, and do it again (you can go through for free as many times as you want if you don't pass, at least in Oregon). I started at about 3000ppm with the stock SA exhaust and no working smog equipment, and I ended at 219ppm with a janky exhaust with a mostly blowout cat and a rigged smog system.


Ok, that got a little long but let me wrap this up. If you can go through for free, I would first start by adjusting the idle mix and seeing how that changes the numbers (leaner does not always mean lower HC's and all). After that, then try some 'tricks'. I should mention that my port-air port was filled with epoxy by someone, which is why I had such terrible results at first. Once I figured that out it took me a couple days to chisel out all the resin with a combination of tools. While I doubt that's your issue, I wouldn't put it past checking if you're still having issues.

Best of luck with smog, and I hope something I recalled up there was at least slightly helpful.

Ottoman5000

iTrader: (1)

That’s awesome... thank you so much. Time to go mess with