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QUESTION CONCERNING SPARK PLUGS..... 850

posted by  Montalvo on  Fri Apr 8 13:32 CST 2005
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HELLO EVERYONE,


I HAVE A '95 850 TURBO, AND I INSTALLED A CATCO PERFORMANCE CAT, TWO NEW BOSCH O2 SENSOR (15738-UNIVERSAL) AND A DAWES AIR/FUEL METER, BOSCH DIST CAP & ROTOR. NOW, ON THE SPARK PLUGS, I WENT TO THE AUTO PARTS SHOP AND THE COMPUTER LISTED CHAMPION RC9YC PLUGS. I KNOW THAT MY CAR USES RC7YC......RC9YC BEING A HOTTER PLUG, COULD THESE PLUGS CAUSE MY CAR TO RUN LEANER ? THE REASON I ASK IS BECAUSE BEFORE THE PLUG CHANGE MY METER WAS INDICATING THAT IT WAS RUNNING A LITTLE ON THE RICH SIDE. WHICH IS PERFECT DUE TO MY MANUAL BOOST CONTROL. NOW WITH THESE HOTTER PLUGS I'M RUNNING LEAN AND I HAD TO DISCONNECT THE MBC. IF THE PLUGS ARE NOT CAUSING THE CHANGE, THEN WHAT COULD BE CAUSING IT TO RUN LEANER?


THANXS IN ADVANCE








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    QUESTION CONCERNING SPARK PLUGS..... 850

    posted by  Wallie on  Sat Apr 9 03:20 CST 2005
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    last visit: Sun Oct 3 16:18 CST 2010
    [RELATED]

    do you have the MBC in line with the ECU or are you running it with the ECU bypassed? Either way is possible with the latter of the two leading to lean conditions under high boost at low RPMs








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      QUESTION CONCERNING SPARK PLUGS..... 850

      posted by  Montalvo on  Sat Apr 9 04:03 CST 2005
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      No, I had it with the ecu....but my meter still reads lean after taking the mbc off....








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        QUESTION CONCERNING SPARK PLUGS..... 850

        posted by  Wallie on  Sat Apr 9 04:38 CST 2005
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        last visit: Sun Oct 3 16:18 CST 2010
        [RELATED]

        How many wire are the Bosch universal O2 sensors? Did you have to splice and solder them in? Curious on that point but it could be the hotter plugs too, put in a set of 7s without changing anything else and see what you get.








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          QUESTION CONCERNING SPARK PLUGS..... 850

          posted by  Montalvo on  Sat Apr 9 07:36 CST 2005
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          The o2 sensors are 4 wire and I used the bosch posilock (splice) that came with it to connect the oem connector. Just cleaned the old spark plugs and reinstalled them. Nothing changed. I metered the 02 sensors and they are trying to adjust the mixture, and when my meter indicates a air/fuel adjustment (trying to go richer) I hear my air pump kick on and pumping air into my intake. So my o2 sensors are trying to do their job. Now when I first installed everything, the meter was showing a good mixture ( just alittle on the rich side ). That stayed like that for a full day. I'm wondering since my fuel gauge light came on right when everything change and it went lean and stayed so. Could my fuel filter be causing a restriction and not allowing more fuel to reach my injectors? Can a fuel filter thats at the verge to go bad cause it to go lean?








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            QUESTION CONCERNING SPARK PLUGS..... 850

            posted by  Wallie on  Sun Apr 10 01:37 CST 2005
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            last visit: Sun Oct 3 16:18 CST 2010
            [RELATED]

            Well it sounds like the sensors are working from what you've described and sounds like the plugs can be eliminated. The fuel filter could really be a stretch as you've described the symptoms but when was the last time it was replaced?








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          QUESTION CONCERNING SPARK PLUGS..... 850

          posted by  someone claiming to be meh on  Sat Apr 9 06:40 CST 2005 [RELATED]

          Do the plugs look like they are running lean?
          As for the sensors, I thought it was recommended that universal ones be avoided, and that the proper Volvo part should be used?







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