Yo everyone,
I had issues with smog a few months back on a 88’ I bought last year. The guy told me I needed a valve job due to low compression but the motor has 280k on it so I just rebuilt the whole thing. Anyway I finally got it all back together and it runs great but when I took it to get smogged the guy said he could hear an exhaust leak when I pulled up and wouldn’t even touch it. There is a metal line coming out of the muffler going back to the engine bay that was going to nothing when I pulled the motor. He is saying there’s supposed to be either a pulse pump or an air/smog pump that plugs into that but I have no idea what he’s talking about. The previous owner put in a new carb so I was thinking this pulse pump might have been on the carb? I’m lost. Any help pointed in a direction would be awesome
-joe
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Yes, the guy is correct. I can't remember what it's called, 'air suction' maybe? Anyway, download the factory service manual (FSM) here, go to the emissions section, and you will find info on it there. I might have the name wrong but if you flip through that section it will be obvious when you see it.
Thanks for the responses, that FSM will help me a lot.
So from what I can see it plugs into the AS valve mounted on the air cleaner, which I don’t have or even have a spot for on my cleaner. I fount this on eBay if it’s the right one, I can mount it on there but would it really stop me from passing smog though? If it’s just pulling air from the cleaner or in the engine bay or exhausting back to the carb or not his reading at the tail pipe wouldnt change right?
Yeah looking at the FSM pic Chris posted, it says the AS system supplies filtered air to the cat to aid in burning HC and CO. I would just find a used air filter housing that has the correct AS stuff on it (remember there are a few versions -- Federal and California, and they are different) and swap it in. That should be easy to find and cheap.
Not doing it will stop you from passing smog because the guy won't even test you without it. It's an annoying hoop to jump through but it should be pretty easy to do so I would do it, personally.
Ok I’ll try, I took it back to the shop this morning and told him to test it anyway… gross polluter haha. CO number is about half of what it was before the motor rebuild but still not passing. I’ll order that and try to hook it up, maybe mess with the carb a little too, might be running too rich
You don’t need to mess with the air filter at all for the stock set up. The AS filter just bolts to the fender area and pulls clean air in from there to likely improve the catalytic converter “burn”. Air flow is controlled by the reed valve and I don’t know how much this may help you on smog.
Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"
In remembrance of my friend ARCHINSTL:
T4WD augury? "Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
I’m not much help, no smog testing in rural Missouri. You might start a new thread specific to smog testing. I would expect petros and a few others to reply.
Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"
In remembrance of my friend ARCHINSTL:
T4WD augury? "Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
I'm not sure that installing it would make much difference to the smog results. I think it just allows filtered air into the cat (right now, your pipe is drawing in unfiltered air, but still drawing in air). It also blocks off exhaust coming out from that pipe during situations when it is under pressure. Chances are, by now the cat is clogged anyways and not really working.
Also, my old 1978 Volvo had an actual, belt-driven "pump" that sent air down that pipe to the cat, but the Tercel just relied on the natural draft of the exhaust flowing through the system causing a vacuum in that pipe at cruising speeds.
dlb wrote: ↑Tue Jan 30, 2024 12:50 pm
it says the AS system supplies filtered air to the cat to aid in burning HC and CO. I would just find a used air filter housing that has the correct AS stuff on it (remember there are a few versions -- Federal and California, and they are different) and swap it in.
Whoops, I was mistaken here. I didn't realize the AS system has its own filter and isn't connected to the air filter housing. That actually makes it even easier to replace though so that's good.
Agreed with Mark on your cat probably being clogged, most old ones are.
