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MISSING/HESITATION AT FULL THROTTLE-FULL BOOST 850

HELLO LIST,

MY 97 850 GLT TURBO HAS DEVELOPED A HESITATION UNDER FULL THROTTLE. I CHANGED THE CAP AND ROTOR AND THIS HAS MADE A GREAT IMPROVEMENT THE HESITATION IS ONLY INTERMITTANT INSTEAD OF CONSTANT LIKE IT WAS. THE ROTOR AND CAP WERE VERY WORN AND THE CONDUCTORS WERE BURNT AND PITTED. I AM THINKING OF CHANGING THE IGNITION HARNESS BECAUSE IT IS ALSO AN ORIGINAL PART. THE CAR HAS 110K MILES ON IT

RUNS GREAT AND GETS GOOD MPG BUT THIS HESITATION THING IS MAKING ME CRAZY.

ANT SUGGESTIONS?

ANY RECOMMENDATIONS FOR FUEL SYSTEM CLEANERS?

I THINK THE PROBLEM IS ELECTRICAL SINCE THE CAP AND ROTOR MADE SUCH AN IMPROVEMENT, BUT I AM OPEN TO ANY SUGGESTION/ADVICE

THANKS

DAN








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    MISSING/HESITATION AT FULL THROTTLE-FULL BOOST..... Plugs/Wires 850

    Yeah I'd look at the sparkplug wires they commonly give you that hesitation and miss under load when one or more start to go tits up. You can pull them and check them with a ohmmeter if you want to. Wiggle them around while you test with a ohmmeter lead at each end. You shouldn't see more than 10,000 ohm resistance in any of them and not more than 1,000 ohm difference between any two wires. But after 100k miles they should be changed. Sparkplugs are your choice. I've seen good results with any Bosch or NGK. Get some carb cleaner like Berryman's Chemtool spray (Walmart or anywhere) and cleanout the throttle body too. Make sure there's no moisture in the sparkplug wells and put some dielectric grease in the boot before you slip it over the sparkplug to help seal out moisture. Put some on the cap end too. Good luck ....... Mike








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    MISSING/HESITATION AT FULL THROTTLE-FULL BOOST 850

    Dan,

    I had a hesitation problem once. It was never noticable at highway speeds, but at idle and slow speeds you could feel it. No codes, so I let my mechanic check it out. It turned out that one of the spark plugs was developing a crack. The previous owner did it the cheap way and installed basic volvo plugs. My 850 model is a turbo and requires platinum plugs. Replaced em, and the problem never returned.








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    MISSING/HESITATION AT FULL THROTTLE-FULL BOOST 850

    Have you tried changing out the spark plugs too? Also you may want to get the O2 sensor checked out. Even though it's not tripping a code, it may be at it's lifes end. Oh yeah, could you please NOT YELL ALL THE TIME, thanks!
    --
    '95 Volvo 854 Turbo: Gold Edition
    K&N Air Filter, Leather, 6 disc CD-changer, Rear Spoiler
    tinted windows








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      MISSING/HESITATION AT FULL THROTTLE-FULL BOOST 850

      Jay,

      I am not actually yelling just that I am at work and the application i use for business is case sensitive and we use CAP's. I have changed the spark plugs to Bosch platinum +2's but I think I will try some Bosch Super's Copper Electrode, i hear that turbo's like the standard all copper plug's.

      i have had a few codes from the ECU recently both times it was for "misfire" i do not remember the cylinders that were affected. This why i tend to believe that i have an ignition problem. Would the 02 sensor failing cause a hesitation under WOT?

      Thanks for the info,

      Dan
      1997 850 GLT Turbo, amsoil hi flow air filter, custom cat-back magnaflow exhaust with muffler relocated to behind rear tire, crossdrilled front brakes, dawes device set at 8 psi (I have had this installed for close to 1 year and this is not the cause of the problem that i am experiencing now, stock boost approx 6 psi)A pillar pod/boost gauge, rear spoioler, Black/black tint, tan leather, sunroof.








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        MISSING/HESITATION AT FULL THROTTLE-FULL BOOST 850

        I'd go back to OEM plugs for the car. I did and my mileage went from 20 to 22.3 in the Denver. 28 on the highway at 80+.







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