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Thread: No spark Grid issues - Have gone through checkdowns

  1. #1
    Join Date
    Jun 2018
    Posts
    2

    Default No spark Grid issues - Have gone through checkdowns

    Car was hooked up w/ 7720/7730 and 8261 and was running fine. I was letting it sit idle and the car cutoff. I thought it might have been fuel level so I filled the cell and tried to restart and only have cranking.

    So here is where I am at -

    Checked for spark - nothing

    8261 Coil Check
    -Checked Primary/Secondary resistance on coil - at spec as listed on MSD site
    -Replaced with Blaster 2 coil and no spark from coil to main distributor wire

    7730 Box Check Down
    -When cranking the 7730 box has the green LED light that flashes during cranking to indicate <500 rpm and shows no active alerts
    -Connecting to a laptop shows voltage and rpm during cranking
    -Spark is ENABLED
    -Network Ignition
    -Red wire PIN 15 from 7730 has a 12v switched power source

    7720 Box Check Down
    -Used a single wire and tested the 7720 box female connector ORANGE wire (PIN 17) - has power 12v + when battery is turned on
    -When connector between 7730 and 7720 is connected, the 12v switched source PIN 34 has 12v +
    -Checked continuity of PIN 33 white at 34 pin to 4 pin connector and the connection point is fine
    -Checked continuity of PIN 34 red at 34 pin to 4 pin connector and the connection point is fine
    -Made jumper wire from 3 wires using wirenut on one side and inserted other ends into 7720 box female connector holes orange/red/white which should then isolate the 7720 box. Still no spark while cranking.



    At this point I am at a loss and its sounding like the 7720 box would be bad if I made the jumper and the white wire wasn't passing along the voltage from the Red/Orange wires to send the signal to the coil.


    Is there anything else I could test? Open to hearing opinions on if my thought process is correct about the 7720 box.


    How about the coil tests, even thought they hit spec could it still be bad?

    EDIT - I did also test the magnetic pick up in the distributor and that tested within spec.
    Last edited by Crawlin; 06-11-2018 at 04:52 PM.

  2. #2
    Join Date
    Jun 2018
    Posts
    2

    Default

    No msd tech answers so I will follow up that I bought all new components and started with the single one I thought was bad, the 7720. Sure enough that was the one that was bad. Car started right up

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