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Smog Question

Discussion in '60-Series Wagons' started by Toadhopper, Aug 25, 2006.

  1. Toadhopper

    Toadhopper

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    I've got an 86 60 thats stock with all the smog stuff in tact. It's got 170K on the motor.
    I live just above S.F. so it has to go through a pretty strict test (15 and 25mph treadmill test).
    It passed smog a year (4500 miles) ago when I first got it (put on a new CAT beforehand just in case) and it went through OK. Now, 12 months and only 4500 miles later it failed really bad. The only mod I've done is a new vacuum secondary diaphragm.
    I have to go through a "test only" center so I have to make all my adjustments, get a pre test at another shop and THEN get it tested.
    I adjusted the valves after the first smog check, which improved MPG and power, but i'm not sure if it jacked up the emissions.
    The CO was at 2.43% @ 15mph and 2.55% @ 25mph
    The HC was at 180ppm @ 15 mph and at 182ppm @ 25mph
    I noticed that the timing was at 6BTDC when it passed and at 10BTDC when if failed so I know it needs to be retarded.
    My other things I need to change are:

    Plugs
    Oil
    Put in Supreme Gas
    Raise the idle from 650 to about 850-950
    Put in some of that gas treatment

    Also, I know I need to heat up the cat before I go in.

    Does anyone have any other suggestions?

    I'm not sure if gapping the plugs wider or narrower than spec would make a difference.

    Any advice would be much appreciated!
    Bryan
     
  2. 2mbb

    2mbb SILVER Star

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    What's your residual oxygen (O2) level? It its at or near zero percent then you're either running too rich or there is something wrong with your air injection system.

    If you continue to have problems you might take it in to Gary Kardum at Mudrak's in Sonoma. If you want to do it yourself, then you should get the emissions manual and start checking for proper operation of the various systems.
     
  3. Toadhopper

    Toadhopper

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    Thanks for the reply!
    My O2% was at 0.0 for both the 15 and 25 mph tests when it failed and 0.0 and 0.1 when it passed.

    Thanks for the suggestion about Gary, i spoke with him today and he's the one who gave me the suggstions on the idle timing and other stuff as well. I was hoping everything was still working since it passed just a little while ago.

    Thanks again!
     
  4. Live to Ski

    Live to Ski

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    Well, I'm in the same boat here in San Diego. Nubers are as follows:

    15mph/2354rpm/11.6 %CO/4.6 %02/126 HC/0.09 CO%/321 NO......Pass
    25mph/2419rpm/11.7 %CO/4.3 %O2/125 HC/0.10 CO%/370 NO....fail HC (s/b under 101).

    I just had the manifolds removed, welded, machined and installed along with a new air rail. I also just intalled new vacuum lines routed according to the tech manual.

    I know the idle is too high, it hesitates when hot (no choke), and there is some kind of rpm dependant wistle I notice when shifting (upwards of 2500 rpm). Also, i did not adjust valves as they were fine about 1500 miles ago.

    Now, I was unable to check the operation/plumbing of the air pump, and I couln't get to the idle and fast idle screws for adjustment. Other than that, the only other issue is a bad vtv valve going to the choke loader (i don't think that should have any bearing on smog).

    Any advice here would be most welcome.
     
  5. lovetoski

    lovetoski SILVER Star

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    I seem to remember a series of posts on here a few years ago about using Coleman white gas to help pass emissions? Formaula was something like run the truck to 1/4 full, put 1 gal of white gas in the tank, get tested, pass, then fill up w/regular gas.

    Or is this a wierd dream? Does it actually work?
     
  6. Cruiserdrew

    Cruiserdrew SILVER Star

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    A timely post. I just failed smog last week with numbers similar to toadhopper. The CO and HC means it's running too rich I think. I did the tuneup routine-new plugs, wires, air filter, set timing and the numbers dropped a lot. I now pass at 25 mph and just barely don't make it at 15 mph. I'd been planning a carb rebuild anyway, so I sent it off to Jim C to be rebuilt. If it still fails, it will be time to really dig into the smog system. Mudrak is not interested in smog repairs-I asked! He did give me a bunch of tips though.

    Once the carb is back, I'll install, adjust the valves and try again. Good luck Toad, these 60s barely pass when under the best of circumstances, so it doesn't take much to fail. If you find out a major secret, please let me know.
     
  7. loeky

    loeky

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    i'm also in the same boat. i've been close the two times now that i've tried to go in. i need to test the fuel pump to make sure it's not letting in extra fuel. will do this weekend. there's a test in the FSM for vacuum pressures. that can make it run rich as well.

    i also need to go in and get a thermometer pointed at the cat to make sure it's on par. not sure if a new one would fix the issue.

    what did Mudrak have for tips? would love to know as it's coming down to the wire on this.
     
  8. Toadhopper

    Toadhopper

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    Hey Drew,
    Misery loves company! I'll let you know if I find a silver bullet.
    I'm thinking of skippin all the way to a SBC sooner than later.
    I'm gonna try the tune up route...s***, it passed easily a year ago so I hope I can give her a little CPR and It'll be behind be for a couple years.
    Toad
     
  9. Cruiserdrew

    Cruiserdrew SILVER Star

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    If you go SBC, can I have your 2F? I sort of need one for my 71.
     
  10. Toadhopper

    Toadhopper

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    No worries, Its all yours. I'll just have to remember not to put a bullet through the block once i'm done:D
     
  11. Toadhopper

    Toadhopper

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    Gary said to raise the idle, retard the timing, change the oil and plugs and put in prem gas. I think adjusting the valves and some of the gas tank treatment would be helpful.
    He also suggested to takl with BAR and try to get off the "TEST ONLY" list so it can get diagnosed and fixed the same place. Also, like you said the CAT needs to be good and hot. :ban: Oh yea, PRAY
     
  12. Pin_Head

    Pin_Head

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    It is failing both CO and HC at all speeds. High CO means it is running rich:
    clogged air filter, plugged air correction jet or malfunctioning power valve are a few possibilities.

    HC is unburned hydrocarbons. They can come from misfiring or leaky exhaust valve and a bad catalyst / air injection system can contribute to high HC.

    You can't raise the idle speed above the specs or they will fail you.

    Thbe "test only" station is no big deal.

    I would start by checking the compression.
     
  13. Toadhopper

    Toadhopper

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    Thanks Zippy!
    That sounds like a good place to start. The comp check will show me if one of my valves isnt sealing right.
    Does plug gap play any signifigent role?
    Does power valve have s screw adjuster next to the idle adjuster?
    If I adjust the idle mixture screw on the carb will that affect the mix at the higher RPMs?
    Toad
     
  14. Pin_Head

    Pin_Head

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    Not unless it is so wide that it can't spark across the gap.


    No. Im not sure about later carbs, but on earlier carbs the power valve is operated by the ECM and a VSV. Check your smog manual.

    No. It only affects idle mix, which is why your problem is more likely upstream of the idle circuit, like the power valve or air correction (aka slow) jet.
     
  15. Toadhopper

    Toadhopper

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    Thanks again Zippy.
    I'll call CDAN tomorrow to order my Emissions manual.
    Toad
     
  16. Cruiserdrew

    Cruiserdrew SILVER Star

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    Just to correct one thing Pin Head said, the idle circuit is always on. So if its very rich, it will cause relative richness at all RPMs. I need an emissions manual as well. On 60s the idle mixture screw is present but is blocked off, so you have to drill out the plug to make adjustments, at least that's what I remember.
     
  17. Pin_Head

    Pin_Head

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    Fuel flow in the idle circuit is determined by vacuum. At speeds above idle, the vacuum at the idle port drops compared to the vacuum at the main nozzle. Therefore the amount of fuel from the idle port drops as fuel is pulled out of the main nozzle. At speeds above idle, the amount of fuel delivered by the main nozzle is much greater than that from the idle port, which is why adjusting the idle mix has virtually no effect on the mixture at high speed.
     
  18. Toadhopper

    Toadhopper

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    GOOD TECH!
     
  19. SigMan

    SigMan

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    Check the TPS

    I suggest for you to check out the TPS. The TPS contact may be worn out and need replacement. Worn out contacts will cause the engine to hesitate when idle as well as causing the timing to go way off.

    Cheers!
     
  20. IH8Wood

    IH8Wood

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    The test only requirement is a pain because the tech who tests can't make any adjustments. I went to a mechanic I know who tweaked the timing and carb to get it in spec and then I took it to the test only place and of course it passed. Then I readjusted everything so it actually runs OK.
     
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