85 MKII Failed emissions from high HC

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  1. #1

    85 MKII Failed emissions from high HC

    I just picked up my first mkii and after my 2 hour wait I failed emissions. Any insight would very much be appreciated. Thanks.
    Here are the numbers,
    Fuel cap: Fail
    Hydrocarbons in ppm:
    -Loaded reading: 324, Loaded standard: 220
    -Idle Reading: 479, Idle standard: 220
    Carbon Monoxide in %:
    -Loaded Reading: 1.02, Loaded Standard: 1.2
    -Idle reading: .6, Loaded Standard: 1.2

    On start the idle is a tad high at around 1.4k rpm but then settles down to 1k and stays there. It doesn't idle rough at all. The spark plugs were recently replaced along with the distributor cap and has a clean air filter as well. After getting back from emissions I checked for any vacuum leaks (not that well) and noticed that one line was broken clean through. And that after the EGR vacuum mod its connected to some sort of filter and not to the 3 way T splitter that feeds into the EGR. I added some pictures below. I also checked my timing which had top dead center at 0 degrees. Should i change that over to 10 degrees? Could this make me have such high HC? What would you suggest be my first steps in resolving this issue? Also what does the line that broke do? It's the 3rd picture "img2.jpg" with no tube attached. Thanks!
    Attached Images Attached Images

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  3. #2
    CelicaSupra.com Member
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    The 'broke" line is a dead end and was not connected. When I rebuilt my 1st 5MGE I spent some time looking for the same connection only to find out it is not used. The correct timing will help big time. Definitely remove and clean the EGR.

    A friend just told me that Champion or NGK copper plugs are the best plugs for smog tests in older cars. Supposedly they only last 2-3k miles before weakening though. A fresh oil change with 40W or 50W could also help. Make sure the car is warm after running it for at least 10 minutes.

  4. #3
    Founding Member pdupler's Avatar
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    Absolutely you need to make sure that all the vacuum lines are connected according to the diagrams and set the timing correctly. Also, you need to make sure the egr valve is actually functioning. You can get a hand-operated mityvac vacuum pump from Harbor Freight or online for like $20 and its invaluable for all sorts of vacuum system testing (you can never have too many tools). Another thing you commonly find on these cars is the egr pathway is blocked with 30+ years of soot. I believe there is a thread on here somewhere explaining how to clean the egr passageways, but it involves knocking out a tiny freeze plug in the intake manifold to get access to it.
    Phil D.
    85 Silver 6m-gte, completed 2000

    "I always observe the speed limit. I see those DAMNED signs everywhere."

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  6. #4
    CelicaSupra.com Member AJ's Avatar
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    IF the test was in California, the timing would fail you have to be set to factory spec.

    Fresh fuel, engine at operating temp (cannot sit and cool off prior to smog test) I usually drive 10-15 on the freeway prior to testing...

    EGR would usually often affect NOX numbers...

    For the vacuum line find a post from Sowsley and check his sig for '82 links for emissions
    Regards,
    Arch
    '86 Supra MA67
    Brullen 2.5" Exhaust, HKS Fly w/7MGE clutch,ST Springs, RC Intake & TB, 2.8GT & XX emblems, Factory Add on Rear Shoulder belts, Pioneer DEH-P2000 AM/FM/CD w/CDS-P5000 CD Player, Compomotive CXNs 8x16

  7. #5
    CelicaSupra.com Member AJ's Avatar
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    Sorry my bad I thought the Sup was a '82... bad eyes...

    Check this link for vacuum routing should be the same for a '85

    2 pic down
    EGR System (pg 3-16)
    https://www.celicasupra.com/forums/s...hlight=Sowsley
    Regards,
    Arch
    '86 Supra MA67
    Brullen 2.5" Exhaust, HKS Fly w/7MGE clutch,ST Springs, RC Intake & TB, 2.8GT & XX emblems, Factory Add on Rear Shoulder belts, Pioneer DEH-P2000 AM/FM/CD w/CDS-P5000 CD Player, Compomotive CXNs 8x16

  8. #6
    CelicaSupra.com Member Zerodrag's Avatar
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    I believe high NOx is usually EGR, or a bad catalytic can also do it.

  9. #7
    You guys are great. Thanks for the help I'll let you know how it goes tomorrow and what I find out tonight

  10. #8
    My car would not pass smog. I changed the catalytic converter and that did the trick.

  11. #9
    Boosting Mod SilverMk2's Avatar
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    Hydrocarbons come from unburnt fuel or oil passing thru. I'd check for vacuum leaks, bump the timing to stock, make sure everything is tip top, and rerun again.

  12. #10
    CelicaSupra.com Member supra_toy's Avatar
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    Check your timing again, Its unlikely it's actually at 0 degrees (it would likely run poorly enough that you'd notice something is wrong), there is a test plug that needs to be shorted to get correct timing readings. 1000 RPM idle is too high, should be between 6-800 rpm.

    I just got done doing this BS here in Oregon, spent the whole day, new Cat, plugs and oil... and still just barley made it through (tried to fail me for Smoke too) What do they expect on a car with over 300k on it?!?

    will

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