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Thread: 550-400 - I think my ECU might have fried.

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    Default 550-400 - I think my ECU might have fried.

    Hello Forum members. This is my first post, I'm a 50 year old Italian living in South Africa since 3 years of age.
    I love my 4x4ing, mostly fabrication, and am well equipped tooling wise at home, lathe, mill, tig, mig etc.
    I studied electronic engineering after graduating school, but honestly never really used it that much.
    I own my own graphic design company which is my primary source of income.
    Back in 2012 I imported a Holley Avenger 550-400 for my 400 cube CJ-7.
    There is zero support on this product locally, and any spares required is purely direct import and hope what you get is good.
    Unit has run for years problem free, small cap Chevy HEI distributor so timing is fully electronically controlled.
    2 months back I get a bad stumble just off idle, developed into a bad miss, and then intermittent stall once hot just off idle.
    You can hear the fuel pump relay powering off and then back on again in a matter of milliseconds,
    but by then she's stalled and you need to restart, which takes a fair bit of cranking before she starts up with a cough and a spit.
    I replaced everything I could electrically, new HT leads, new ignition barrel, all new relays, new spark plugs,
    new complete distributor with new module & hall coil, new fuel pump and wiring, even changed the timing chain and gears 'just in case'.

    I even bypassed all the vehicle electrical by wiring coil, ECU and related hardware directly to battery via a mechanical switch as my
    ignition, and she seemed to work fine for a few weeks, until today, where the stall and miss started all over again.
    Got home, parked in the garage and with the lights off raised the hood only to be met with a nice fat electrical spark discharge
    between the HT coil positive, negative and output terminal, nice blue hue.
    Coil is a standard canister flamethrower branded item.
    Anyway, almost died of fright, killed everything and stood back a while.
    Come to start the Jeep again and nothing, fuel sender relay will not power up at all, dead.
    So once again I isolated everything electrical TBI wise, on next ignition on the handheld device showed no sync.
    Removed all power and left her standing for an hour or so, on reconnect she syncs, but no fuel pump prime. Red dot on "Perform TPS!"
    So I thought let's start from new, go into Wizard and reload all specs and files, perform TPS, all good, but still no fuel pump prime at all.
    Turn power off and then on again, sync is good, however, still red dot on perform TPS.
    So here I am, at a total loss, I honestly wonder if the sparking between the coil terminals has fried my ECU.
    Is there any way to force a factory reset, just in case, or is that the Wizards function?
    I'll take all the feedback I can get right now, I'm at a total loss. Thank you to all. Kind regards - Marco
    Last edited by Marcochezzi; 02-19-2017 at 01:30 PM.

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