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86 CP Misfire

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    86 CP Misfire

    Please help! I took my 86 out for a ride and after it got warmed up it started missing like crazy but only when accelerating. Idles perfectly smooth. Any ideas what can be going on here? I am new to these cars and used to carburetors lol

    Any help will be so appreciated

    Thank you
    Sal

    #2
    How old are the coil and ICM?


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      #3
      I really don’t know, the coil looks original. Not sure about the ICM. I’ve only had the car about 4 months.
      Are those known problems with these?

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        #4
        age of the plugs, wires, cap, rotor, and condition of the terminal on the coil would be what I want to know. Under the EFI system its an engine designed in the 1950s and needs the same kind of maintenance.

        The ignition modules go bad but I wouldn't jump to replacing it before knowing the basics are in good operating condition. High load, low rpm misfire very much sounds ignition related to me.
        86 Lincoln Town Car (Galactica).
        5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

        91 Lincoln Mark VII LSC grandpa spec white and cranberry

        1984 Lincoln Continental TurboDiesel - rolls coal

        Originally posted by phayzer5
        I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

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          #5
          Thank you so much! Gives me a place to start. Does the fact that the misfire is worse when the car is hot give you any clue as to where to start?

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            #6
            If there's over 80K miles and the timing chain is original, it could be the plastic cam gear going away and allowing a lot of slack.

            If it is solely temperature related, it could be the computer temperature sensor near the thermostat housing (2 wire) or the ICM starting to go bad.

            Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
            rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
            Originally posted by gadget73
            ... and it should all work like magic and unicorns and stuff.
            Originally posted by dmccaig
            Overhead, some poor bastards are flying in airplanes.

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              #7
              What gadget said. The ignition system is taxed the hardest while under part throttle load. I deal with that every now and again with my GM TBI stuff. Often ends up being the contacts at a plug or at the cap. This time for me, it was cylinder #3- the boot had gotten a tear in it somehow. Last year it was one of the terminal ends not making good contact at the cap on cylinder 4 or 6. In both cases, it ran fine under all conditions except part throttle acceleration.
              1985 LTD Crown Victoria - SOLD
              1988 Town Car Signature - Current Party Barge

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                #8
                Well so far I’ve changed.....
                Plugs
                Cap
                Rotor
                Wires
                Coil
                ICM
                Fuel filter
                Cleaned injectors
                Tested injectors
                Checked compression

                And no change

                Any other suggestions?? Please!

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                  #9
                  I think I would pull codes before throwing more parts at it.

                  My thoughts include throttle position sensor, EGR issues, oxygen sensors.
                  1990 Country Squire - weekend cruiser, next project
                  1988 Crown Vic LTD Wagon - waiting in the wings

                  GMN Box Panther History
                  Box Panther Horsepower and Torque Ratings
                  Box Panther Production Numbers

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                    #10
                    if the codes get you nowhere, about the only other thing is the pickup in the distributor

                    Whats your plug wire routing look like? 7 and 8 cannot lay next to one another or it can cause some problems too. If you still have the wire routing clips on the valve covers, put them on opposite ends of the clips.
                    86 Lincoln Town Car (Galactica).
                    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                    91 Lincoln Mark VII LSC grandpa spec white and cranberry

                    1984 Lincoln Continental TurboDiesel - rolls coal

                    Originally posted by phayzer5
                    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                    Comment

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