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Failed Emissions

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by jimmyjack, Dec 5, 2000.

  1. jimmyjack

    jimmyjack 1/2 ton status

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    For the first time in the nine years I've owned my blazer I failed emissions. The hydro carbons were alrightm and the idle CO was 0.03 out of 1.20, but the loaded test was 2.09 out of 1.20. The CO tests have always come back almost identical between the loaded and idle. I plugged up the EGR valve vac tube cos it was leaking and I'm pretty sure this is why it failed, but wht the big difference? Any ideas? The oil could use changing, but I'm not sure if it would effect anyhting. The funny thing is it passed the equipment test. It's barely hooked up.

    creepin' and crawlin'

    Jim
     
  2. CrazeeBush

    CrazeeBush 1/2 ton status

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    FIrst I'd check the spark plugs, wires and dist cap. AMke sure the timing is right and run premium gas a couple tanks before you go. I usually put 2 bottles of alcohol in the tank and run it hard on the way to be tested. I haven't had any problems to date.


    -JoSH
    crazeebush@aol.com
    http://josh.coloradok5.com
     
  3. jimmyjack

    jimmyjack 1/2 ton status

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    The plugs are pretty new but I found a burnt wire today and the cap was a little crappy. I replaced the EGR gasket and I'll run a tank of premium and then see what happens. Thanks for the advice, I was stunned when it failed.

    creepin' and crawlin'

    Jim
     
  4. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    It's the EGR. The EGR is not on at idle hence your unchanged reading. Your unchanged reading also indicats that your mix should be close to the same so the carb is holding it's settings.
    The EGR comes in about 1500-2k depending on the motor. It delutes the mix and drops the CO as a result. Hook it back up and you should be ok. A quick test to see if it's working is while at idle apply vac to the EGR it should run rough and maybe even stall. if it does that then it's working. if it doesn't change either the diaphram is bad in the EGR or the ports and passages are plugged.

    Diging it in the dirt with my K5's
    Grim-Reaper
    http://grimsk5s.coloradok5.com/
     
  5. Thunder

    Thunder 3/4 ton status

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    Grimm's right. A bad or inoperatave EGR will fail emmissions most every time.
     
  6. JimmyDie6.2

    JimmyDie6.2 1/2 ton status

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    as a side note, stay away from premium fuel when you go to the sniffer. The higher the octane rating the longer the carbon chain in the fuel. Hence higher emmisions byproduct. fill her up with 87 and dump in "guaranteed to pass emissions" stuff,(its sold at pep boys), It worked on my sisters s-10 after it failed. What state are you in??? Just curious......................js
     
  7. jimmyjack

    jimmyjack 1/2 ton status

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    I'm here in Az. They move the cars in and out like cattle going to slaughter. I'm amazed they can keep the machines clean and calibrated(yeah right). Last year I drove my wifes car thru and it failed, I made a u turn, went right back in to a different bay and passed with flying colors. I told them I just failed three minutes earlier in the next bay over but I don't think he understood what I was saying to him. CO poisoning does that to you. I'll let you know the results in a few days.

    creepin' and crawlin'

    Jim
     
  8. k5king

    k5king 1/2 ton status

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    hey, if you can get your hands on some alchohol(for the truck!!!) dump some in your tank...if the local race track is open go there and get a couple of gallons,just one or two...then dump it in tank and fill up to about a quarter to half tank...i guarantee you'll pass!!!!! we use the little bottles of anti freeze for your gas here after the race track closes and put in like six or ten bottles but only put in about 3 gallons in the tank,,,just enough to get to the emissions station and to the closes gas station....the deal is that you have to burn more alky to make up for the same amount of fuel,,,a fuel inj. system just knows that a certain amount of fluid is passing by but cannot tell wether it is gas or alky so it runs a little lean and the alchohol burns A LOT cleaner than gas so no high readings!!!!! YYYEEEAAAAHHHHH!!!!!!! GO ALKY!!!

    ANYBODY LOSE THEIR JEEP????????[​IMG]
    I JUST FOUND ONE UNDER MY BLAZER!!!![​IMG]
    [​IMG][​IMG]
     
  9. tom

    tom 1/2 ton status

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    Anybody know what kind of alcohol? The same stuff you can sometimes get by the gallon at a paint store?
     
  10. k5king

    k5king 1/2 ton status

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    i don't know about that but you can get little bottles of "dry gas" at a local mini mart i believe,,just put in quite a few... they can be a little expensive but i think they are worth it!

    ANYBODY LOSE THEIR JEEP????????[​IMG]
    I JUST FOUND ONE UNDER MY BLAZER!!!![​IMG]
    [​IMG][​IMG]
     
  11. Bigmeats

    Bigmeats 1/2 ton status

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    im pretty sure(90%) its the same as just plain old rubbing alcohol. And that can be found prety cheap!

    Bigmeats

    Carl...75 Blazer...Manhattan IL
     
  12. JimmyDie6.2

    JimmyDie6.2 1/2 ton status

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    be careful you guys don't burn up a valve or crack a piston messing with the alky......but it sounds like a cool idea. By the way as a New Yorker we get cameras in all our emissions stations, (which are all gas stations), they are hooked up to the state capital, If you mess with the machines big brother comes and takes you away.........forever. ....................js
     
  13. jimmyjack

    jimmyjack 1/2 ton status

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    When you say alcohol, I assume your talking about TRICK racing fuel, correct? A few stations here sell it out of the pump but the circle track season is over so I'm not sure if they are selling it right now. My money is on the EGR being plugged up. I did it to "fix" a vacuum leak. Maybe thats where I'm getting my brown exhaust when I stomp on the gas, huh?

    creepin' and crawlin'

    Jim
     
  14. rebel222

    rebel222 Registered Member

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    HA. You guys have it hard. I live in Louisiana. You can just tell the guy you are working on that problem at the time or just give him a soft drink. Also just look over at his old beat up truck and ask if his passed. Not a problem here.
     
  15. Gandolf

    Gandolf 1/2 ton status

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    I was told by a very knowledgeable race engine builder that the oil should be changed just before a smog test, especially with high mileage engines. I asked a smog technician about it and he agreed saying that it does make a difference.

    '89 K5 Silverado 4" lift w/BFG 33's
     
  16. JimmyDie6.2

    JimmyDie6.2 1/2 ton status

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    race gas is A LOT "dirtier" than regualar 87 octane. Becaause of the higher compression ratios of race motors, the fuel has higher ignition point. The fuel accomplishes this with a longer carbon chain. By the way the emmisions stuff that I used in my sisters s-10 is "CRC- Emissions Test Formula", The phone # is 800-272-8963. Give them a buzz if you want, find out where they sell this stuff by you. I do not know if the number is toll free...js
     
  17. 65FL

    65FL Registered Member

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    I am confused by Grim's answer. The EGR is used to control NOX. NOX is formed by high temperature and
    pressure. By diluting the intake with an inert gas (exhaust) the combustion temperature is lowered, thus
    lowering NOX. I don't think that a bad EGR would effect the CO readings, or am I missing something
    here? I was taught that high CO readings indicate incomplete combustion, i.e ignition problems or running
    to rich.

    By all means fix the EGR, but if that fixes the CO problem I guess I will have to go back to the books
    to understand why. Grim, could you explain your answer it has me confused.

    Always trying to learn more,
    65fl
     
  18. jimmyjack

    jimmyjack 1/2 ton status

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    I don't get it. I unplugged, and repaired the egr vac tube, repaired the gasket for the egr, replaced two bad plug wires and it barely idles. It sputters and misses and kicks and bitches and pisses and moans(sorry)but when I give it gas it hauls ass. And the brown exhaust is gone, but when I pinch the egr hose it idles really smoothly. I'm tired and I wanna go to bed.

    creepin' and crawlin'

    Jim
     
  19. 65FL

    65FL Registered Member

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    It sounds like the EGR is stuck open. This is fairly easy to check for. You might have
    to end up replacing it.

    I have been doing some thinking about my statement last night. Basically I am stating
    that the EGR will not effect CO emmisions. The EGR controls NOX, and high CO
    indicates a too rich condition. I would like to revise that statement. If the EGR is stuck
    open, it is putting in to much inert gas, which decreases the amount of available O2,
    thus causing an over rich condition.

    Since you plugged the line to the EGR, you basically took it out of the loop so it
    couldn't effect the CO. I don't know, maybe I am thinking to hard.

    Go back to the basics, what you describe are the classic symptoms of the EGR
    being stuck open at idle. Fix that problem, retest it, and let us know what happens.
    I am really curious to know what the answer is to your high CO.

    65fl
     
  20. jimmyjack

    jimmyjack 1/2 ton status

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    I went to bed, I'm still tired. The engine is driving me nuts. This morning it started first try, ran like a top, no misses, no hesitation, no lag. Pulled into 7-11 2 blocks away, got a soda, started it back up and it crapped out. Sounds like its missing on alternating cylinders. Like every other hole....1-8-3-6-5-7-2- 1-8-4-6-7-2-1-4-3-6-5-7-1- so on so forth. I'm looking at a vacuum leak AGAIN. I plugged up the EGR hose again and it all went away. I'm going back to bed. I have noooooo responsibilities today and I'm taking full advantage of it. "SCREW 'EM IF THEY CAN'T TAKE A JOKE!" Maybe my blazers playing a joke on me! hmmmmmmmmmmmmmm...........zzzzzzzzzzzzz

    creepin' and crawlin'

    Jim
     

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