Trying to pass smog, other repairs

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Medessec
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Posts: 6
Joined: Fri Jun 24, 2022 10:57 am
My tercel:: 1985 Toyota Tercel 4WD SR5

Trying to pass smog, other repairs

Post by Medessec »

Hello everyone!

The transmission is fixed and now shifts pretty well. The thing has been a treat to drive and seems to run very nice.

I took it in for a smog and they found:

-Air Injector Hose Disconnected
-TAC Tube Missing
-Unable to check timing cover riding on pulley
-Failed Emissions (Gross Polluter)

They pointed out that my PPM was far too high (287 versus the maximum allowed 137). I have noticed that it idles kind of high on start, but other than that it seems to run great... is it simply running rich? In your experience, would any of the other listed issues affect this condition?

So, the guy who actually smogged my car was nice enough to point out his encounter with each issue- The Air Injector hose was simply fallen off, so I reconnected it. The TAC Tube I guess is a stove pipe that goes into the intake, and it seems to be missing altogether. What's the best way to source this? Is it metal or rubber?

The timing cover thing... do I have to actually replace the timing cover with one that has a window for the smogger to see the timing? Or can I cut a hole in the existing one?

And would anything else affect a rich-running condition? The previous owner noted that they drilled a hole in the current carburetor, so it ran better at altitude. I'm in Sacramento, so the car is at sea level now. The previous owner did give me another carburetor that is supposedly rebuilt when he sold me the car, so I could swap that in.

Any help would be appreciated!
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Petros
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Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Trying to pass smog, other repairs

Post by Petros »

running too lean or too rich would give you bad readings. You might try the other carb if the one on it has been altered, but sometimes they do not rebuild well and can be troublesome to sort out (there were slight changes to the carbs over the years, all similar but sometimes with different jets, different vac routing, etc). Also you have to take the vac diagram of your engine (available for free down load off t his site), and trace each of your vac lines from start to finish: check for correct routing and for cracks or damage and good fit at both ends. All of the vac lines have to be in proper place and not damaged. In the Factory Service manual (also available for free PDF down load on this site) there is a trouble shooting guide in the emissions chapter and the fuel system chapter that is pretty good at running you through a lot of simple tests to verify all of the components are working properly. There are some California members on this forum that know more about getting the emissions to pass than I do (I tunneled out of California and escaped 38 years ago).

you can carefully cut back the timing cover to expose the timing marks, it is made of plastic. make sure the timing numbers are still visible. also, clean out the timing mark on the front pulley and put white paint in the groove so it is easier to read. make sure it is set at 5 deg BTDC when you get it tested, but I would advise to move it to 10 or 12 deg BTDC after the emissions check (the smog dictated retarded timing will lower your economy but most of all results in hot exhaust that can overhead and damage the exhaust valves, and than that could trash the engine if the valve breaks off...I have seen it in a lot of toyota engines).


Usually the fix is simple, but finding the cause and sorting it out may be frustrating. go through the system checks systematically, do one check at a time. do not make a lot of changes all at once, you may make it worse and not know what caused it. you may have get it registered in another state where the age makes it exempt from emissions (but not in California), some replacement components may not be available.

good luck
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
Medessec
Newbie
Posts: 6
Joined: Fri Jun 24, 2022 10:57 am
My tercel:: 1985 Toyota Tercel 4WD SR5

Re: Trying to pass smog, other repairs

Post by Medessec »

Thanks so much for the pointers Petros!

I ended up swapping the other carb on. I haven't gotten the car tested yet but I spent quite a bit of time adjusting the settings so that it idles fine. It doesn't seem to be running rich... and it hopefully isn't placebo but I could swear it seems to be a tad more perky and smooth with throttle when driving it around. I took photos and video of the vacuum lines on the old carb to make sure all the lines got swapped to the proper positions on the rebuilt one. I also used the factory maintenance guides in the manual to do the adjusting and diagnose little things, and I also found a couple of other things (the two vacuum lines leading to the distributor were not even connected, and one was broken).

I'll probably take the Tercel to get retested after I figure out the timing cover, but I'm not too set on them passing me. My boss and other buddies have let me know about the "smog referee", I might see if they can help at all. I'll hopefully have an update soon.
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