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83 MGM ignition control module question

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    83 MGM ignition control module question

    My 83 MGM has had electrical problems ever since I have owned it. Many shops have thrown parts at it but it has never been fixed. What it does is : It starts when it wants to . If it starts, it is right away. Right now it wont start.
    When it runs it runs perfectly however it quits running whenever it wants to. It could be in an intersection, a stop light, just driving or idling. It may or may not start back up.
    Many parts have been replaced. Lots of money spent. I do not think it is the distributor as it does not have the guts like the older models have. Fuel pump activates, but is it weak ? Don't know if it has been checked properly.

    Ignition control module question. It now has a non California smog (Car is from NJ) module on it with a brown tab on the silver box where the wires go in. CA. smog models have the Blue tab. Wires look the same. When I was attempting to start the car yesterday, the module was getting warm. In my opinion, not good. Module has been replaced several times. Unknown brand on there now. IF I put a blue module on it, will it hurt anything ? I have thought it could be possible that the wrong module was put on sometime before I bought it.
    I am also planning to replace the crank sensor as that part seems to have been overlooked,according to my work orders. Of course a broken wire is another thing that I have suspected all along. I just need to get the car started and out of the garage so I can get to the mechanic I have been using who so far has been excellent. It has only taken me about 11 years to find him.
    Another plan is to start replacing sections of the wiring harness under the hood from connector to connector. I have a known good harness from a donor car.

    #2
    I have never replaced a old style box with the incorrect module to find out if any damage would happen, When I worked on these cars years ago we had good current at the time manuals that guided us as to what module went to what year etc car.

    This is a older car and I seem to remember back then we used to have common problems with the ignition switch separating causing intermittent issues.

    I would start with the basics and find out what is missing when the engine does not start or stalls then will not restart, meaning you will need to have ready a remote starter button a test light and a in line spark tester installed at minimum.

    When it stalls and does not restart do not turn the key to the off position, pop the hood and connect the remote starter button to the solenoid, with the 12 volt test light connected to ground first crank the car over to confirm you no longer have spark at the inline spark tester. then touch the business end of the 12 volt test light to the positive side of the coil with the key on not cranking then key on and cranking with the remote starter button. if you do not have power at the coil suspect the ignition switch, ignition relay or wiring.
    If you have power at the positive side of the coil with the key on and cranking check the negative side also while cranking the test light should light up but flicker on and off quickly if it does not flicker suspect wiring or ignition pickup inside the distributor or module ( if either are bad replace both ) make sure none of the connectors have broken tabs ( common for this type and age of connectors )

    I mentioned leaving the key on if the car stalls then will not start because if the switch is going bad separating etc turning it back to the off position may temporarily solve the problem making it harder to diagnose the problem.
    When I mention ignition switch separation I am just referring to the metal tabs that get bent over clamping the sections together those tabs can loosen up over time as the grease dries up making it harder to operate the switch which will lead the switch to open up or separate.

    The good news is any part in the ignition system is very cheap now just make sure to use good parts Motorcraft if they are still available.

    Chances are your trustworthy tech will just toss a bunch of parts at the car and hope he gets lucky as most of the diagnostic tools and data that was readily available back in the day is not so easy to get or in working order if they still have it.
    2007 Ford Crown Victoria LX Sport

    Comment


      #3
      I always though the EEC-III cars had the yellow insulator. My understanding of those was the blue grommet is the 2 plug style, the yellow is the 3 plug style. The third plug is there for timing retard, either by ECM or knock sensor.

      https://www.ford-trucks.com/forums/1...et-colors.html

      has some info on the various models. Apparently brown and yellow are the same thing? Another post says the brown one has the power wires reverses vs the others. Def check that closely.

      https://en.wikipedia.org/wiki/Duraspark



      finding out what it doesn't have when it won't start would be the place to start. No or weak spark is probably crank sensor related. Might even be as simple as a crusty connection for the crank sensor. Everything drives from that, so if it doesn't have proper signal to the ECM you get no spark and no injector pulse. I believe the connector is somewhere near the front corner of the intake, its not right at the sensor itself.
      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


        #4
        EaOutlaw1969, Thanks for the info. The comment about not turning the key off I never thought of. My days of working on cars are very limited now. Very frustrating as I used to to most of the work. As I have been away from it, I forget the technical stuff.
        Gadget, Thanks for the links. You are right about the crank sensor being a likely suspect.

        I don't think the module should be getting warm when the car is cranking over. Another possible bad part even though it has been replaced a few times.

        Comment


          #5
          Back in the day I found many of these cars with fender or tab mounted relays would get plucked off of the tabs and would be left to flop around with broken harness tabs also. I have seen these relays get filled with water and or end up with corrosion at the spade connectors. same goes with many of the harness connectors. A good plan you already have is to replace sections of the harness under the hood. just make sure the replacement harness has those important tabs or find a away to secure them properly. ( Electrical tape and or wire ties )
          I also forgot for you to look for a old aftermarket alarm system that could have been poorly installed, many of the older pre alarm cars suffered from hacks that would chop cut slice and leave a dangling rats nest under the steering column while installing a cheap china made aftermarket system. if you find anything like that disconnect the battery remove all of the offending rats nest and repair the factory wiring with solder and heat shrink tubing plus new wire loom where needed. Just do not tape up or wire loom the repaired harness until you are sure it is running right and passes a wiggle test.
          2007 Ford Crown Victoria LX Sport

          Comment


            #6
            I really wish there was a source for all of those connector shells. Sometimes the harness is basically fine, but the plastic tabs and such are busted so things end up working loose.
            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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