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Thread: Msd 60143 ls

  1. #1

    Default Msd 60143 ls

    Hello I have a 2003 4.8 from a Silverado,
    put a 5.3 crank
    2005 5.3 rods (floater)
    2005 4.8 flat top pistons (Floater)
    COMP Cams 54-452-11 XFI Xtreme
    Edelbrock carb
    factory coils
    new cam sensor
    new crank sensor
    I converted it to a carb cause it went into a 86 c10, The problem im having is it'll fire up run great but when I shut it down and try to start it back up it backfires through the carb but if I unplug the box then plug it back in after waiting 30 seconds before plugging it in it will start right up, now it doesn't start up every time after plugging it back in but 90% of the time it will, Ive checked the pins and none were bent, 30 amp fused power from the battery with a relay, ground to the head and 4ga ground to the same spot from the battery, I have the dial at LS1. What is going on with it and how can I get a continuous start every time without unplugging the box? Oh and its a LS series 60143 black and its brand new. Thank you.

  2. #2


    Have you connected this unit to a laptop yet to see if you are getting any error codes? On the sensors you are running what brand did you put into them? We have seen issues with a lot of off the selves brands, the one we see the least amount of issues are AC Delco sensors. If you cannot hook up to a laptop what you can do to inspect the sensors is this, hook up a multi meter to the feed wires to your sensors which are going to be either a pink or a orange wire depending on the harness you are using. The pink is 12 volts while the orange is 5 volts, so you will want to inspect to make sure it is getting the correct feed. Then you will want to check the signal wire which is for the cam the brown with the white stripe and for the crank it will be orange with a yellow stripe, depending on the feed wire you should see a fluctuation of voltage on those wires. If it has the pink wire, you should see 0-12v on them, if they have the orange feed wire, you should see 0-5 volts when you are cranking the motor over.

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