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WUR ADUUSTMENT

Discussion in 'Technical Q&A' started by gt500blue, Oct 5, 2007.

  1. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
    1,248
    Texas
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    GT
    Okay, I know there are a lot of threads on this topic, but none that I found seem to help. THe WUR on my 83 308 QV was just replaced by a very reputable shop. However, I noticed today on the way home that when the car warms up, the idle is at 2000 RPM. It's sort of like having cruise control and rather frustrating at red lights!

    It was idleing perfectly (~500 RPM) before this repair. In order for my car to pass inspection, the mixture had to be adjusted and the spark plugs that were in the car were too cold. They were replaced with a hotter plug and the car definately has more pep to it when the accelerator is punched or just blipped. It seems to run hotter (oil and water temp slightly higher), but I don't smell the gasoline anymore when sitting still or parked in the garage like it did before as it was very rich. The fuel lines are new so don't worry about a fuel leak. So, all in all, I think the adjustments that were made were for the better.

    However, now the idle is messed up. Suggestions? By the way, when cold, it idles fine. Only after it warms up does it idle too high. No, the floor mat is not in the way! :)

    Thanks,
    GT
     
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  3. hackrider

    hackrider Karting

    Feb 9, 2006
    153
    Albuquerque, NM USA
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    Dave
    Sounds like they misplaced a vacuum line in the cold start section or on the little temp selenoid/switch near where the WUR is. Like turning on the vacuum in stead of turning off the vacuum to the high idle air bypass. I don't know what they are called but they were disconnected on my '83 Mondial, it never gave me a high idle.

    Hack
     
  4. spiderseeker

    spiderseeker Formula 3

    Jul 22, 2005
    1,708
    Colorado
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    Steve
    Make sure that the floormat isn't give the fast idle condition. They tend to creep over the gas pedal.
    When warmed up the idle should be approx 1000 rpm. 500 rpm seems very low to me.
     
  5. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
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    Note in my post that I said the carpet is not the culprit... I wish that was it. I bought the carpet grabbers from Birdman and they work for a good period of time before they slip out again. But that is not the situation here. I should be more careful, I think the idle was closer to 750 RPM, not 500 RPM to be honest. Either way, 2000 RPM is way to high.

    Only when the car is warm, this happens. I think it may have something to do with the new WUR (aftermarket) settings and the fact that my car had to be adjusted pretty heavily to get it to pass the HC inspection. I have been in discussion with the shop and they have some ideas of what might be causing it. THey said it was very difficult to get it to pass the inspection, since there are no cats or air pump on it.

    They mentioned that we could try to put a restrictor (hose in a hose) on the idle control valve to help less manifold vacuum bypass. They also mentioned that they had to set the idle pretty high to get it to pass since the Hydrocarbons were through the roof at below 1000 RPM. They think that I may be able to back the idle down and it might be okay. I'll let you know.

    The shop is Excellent and I'm sure we'll get it figured out. I just know how busy they are and I want to try and get this nailed down without having to go back in to them if possible.
    Thanks all!
     
  6. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,188
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    Hugh G. Rection
    Warm idle should be around 950 rpm, +-100 rpm. Cold idle is usually somewhere between 1400 and 1500 rpm.

    Why did they use an aftermarket WUR. I would tell them to put a factory oem Bosch unit in, get the CO and idle adjusted properly, and you should be good to go.

    BTW, if the aux air valve is open when the car is warm, then it is defective and needs to be replaced.
    http://www.auto-solve.com/mech_inj.htm#MFI12
    See here for more info on mechanical fuel injection:
    http://www.auto-solve.com/mech_inj.htm
     
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  8. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
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    I mispoke... the WUR is a Bosch unit, but a rebuilt one. I had to send my old one in for a core charge. The Rubuilt bosch unit was $292.95 but is bosch, not aftermarket.
     
  9. Badman

    Badman Formula 3

    Mar 4, 2007
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    Bruce Wayne
    I just went through two of those rebuilt Bosch units which were no good. The third one worked correctly.
     
  10. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
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    Okay, but the question is then, would a high warm idle point to a faulty WUR or a faulty adjustment on the car to get it to pass emission testing? The WUR could still be okay?
     
  11. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,220
    TN
    The best way to test a WUR is to test the fuel pressures. That will tell you if the WUR is working properly. The WUR shouldn't raise your idle. It controls the cold control pressure and warm control pressure. That would point to the AAV.
     
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  13. Badman

    Badman Formula 3

    Mar 4, 2007
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    You'll have to look at the CIS pressures to know if the WUR is working correctly.

    I basically just went through your exact scenario myself. I finally gave up trying to diagnose it myself and took it to the shop. In the end, I had a bad WUR, multiple wiring problems to the WUR and the TTS, an incorrect primary CIS pressure setting, a bad K-jet ECU relay, bad plug wires, a cracked distributor cap, and after all that it turned out my valves were incorrectly adjusted which was what was the cause of the high HC readings (in other words, your symptoms may be caused by multiple issues).
     
  14. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
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    Okay, thanks to all for helping out! The fuel pressures were tested and the Wur was found to be bad, so it was replaced. The idle was fine, but the mixtures were off and had to be tweaked, plugs replaced with hotter ones (in fact, the ones that were in the car were too cold as it was) and the idle was raised a bit to get the car to pass emissions.

    I have to try and bring the idle back down a bit and see if it helps. But the Wur was replaced since it was bad (car ran very rich). But the idle issue was new to the car, but obviously must be a result of mixture and idle changes to get the car to pass inspection. Again, no cats and no air pump. The technician said it was very tough to get it to pass.

    Anyway,. I honestly have not had time to check it out and take a look at all of the good suggestions you have all made. I'll be sure to get back to all and let you know what happens.

    Thanks again!
    John
     
  15. gt500blue

    gt500blue Formula 3
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    Oct 18, 2006
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    Well, I took the car out for a drive last night and found the high idle situation to be almost intermitent. However, it did stay around 2K RPM the warmer the engine got from driving around. I was able to come to red lights and stop signs in 2nd or 1st gear and not push the clutch in until the last second which forced the engine to slow below 2K RPM just before coming to a full stop. Then I was able to push the clutch in to prevent the car from stalling and the idle was perfect at ~ 900 to 1K RPM.

    So, if I am able to "force" the engine speed down below 2K before coming to rest, it will stay there. However, the idle is still high while 'rolling" along in 2nd or 3rd gear. Again, much like a cruise control.

    My follow up question: If the idle was simply set too high, wouldn't the engine go back up to 2K after I push the clutch in at a stop sign? Once I get the RPM below or at the 1K RPM point, she stays there just fine.

    I have yet to find any vacuum lines cracked or disconnected.

    Thanks,
    John
     

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