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Thread: Atomic EFI Problems

  1. #1

    Unhappy Atomic EFI Problems

    I have a '68 Camaro with a 383 stroker engine. I have the Atomic EFI with the latest firmware on it. Prior to restoring my Camaro, the Atomic EFI was running great. The Camaro went through a ground up restoration. In that process, the distributor went bad and I replaced it with a MSD Pro Billet distributor (PN 85551). It has a MSD 6AL original (not digital). The car was running back to normal, started up and great throttle response. The resto person & I decided to let the Atomic EFI control the timing. I purchased a MDS Phasing rotor kit, pulled the distributor, turned it 180 and locked it out, installed the phasing rotor kit and switched over the EFI to control the timing. Well, needless to say, it ran like crap, after screwing with it for a month, we decided to go back to what it was and put it back to normal. It's still running like crap now.

    It will not maintain A/F ratio and timing will not advance or anything. Here's the setting:
    Tach: 950-1025
    ECT: 179
    IAT: 97
    MAP: 17.1 – 21.2 (Erratic)
    Fuel press: 45
    Battery volt: 12.1
    A/F ratio: 14.0 – 16.7 (Erratic)
    Injector duty: 5%
    Ignition timing: 0
    IAC: 68
    There were all at idle.
    Initial timing is set at 15° BTDC.
    MSD Pro Billet distributor springs is light blue & light gray.
    Atomic readings are as follow:
    Engine hard to start (turn over) and sucking air sound. Furthermore, will not take any quick throttle and timing always stays at 15° BTDC on balancer.

  2. #2


    Have you ruled out mechanical issues? Your erratic MAP readings may be pointing to a problem with a bad valve, cam lobe, etc. I'd suggest you do a compression and leak-down test.

    Where are you reading "0 degrees timing"? On the Atomic screen or with a timing light on the balancer? You said you switched back to distributor timing. Did you unlock the rotor and set timing (i.e. 12° BTDC or such) with a timing light? It sounds like the distributor is still locked out.
    Last edited by countrybumkin; 10-17-2019 at 07:03 AM.

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