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Strange m30 grey market problem ECU turns off @ 5000rpm

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  • ForcedFirebird
    Can't figure this thing out! Opened the ECU connector and someone has been in there, soldering some wires, some are cut, and a previous "mechanic" obviously shoved a DMM lead into the face of the connector boogering up the female side.

    So, going to convert to to Motronic 1.3 using a seta engine harness/ECU and CPS. We didn't want to do this yet, but was always in the plan - this way we can eventually go ITB and PnP MS.

    On a good note, found the parasitic draw! The car was pulling several amps with key off. Someone in the past had plugged some relays in with the wrong pinouts. The main relay was always engaged, along with the low speed and headlights. SMDH.

    Word to the wise, just because a relay plugs in a spot, doesn't mean it will work properly. Pin #'s 85&86 are always the energizing legs, the rest are the switched pots. When looking at the bottom of a relay, gotta make sure the pin turned 90° from the rest matches the replacement!


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  • Strange m30 grey market problem ECU turns off @ 5000rpm

    Hoping someone here has some experience with this, it's driving me mad.

    1982 grey market 625sci (so technically it's an m90).

    I just did a full head job on it, super clean 109k miles car. Installed a reground cam, +1 valves, ported to flow to b35 spec, IE headers.

    Car made 210 whp before the mods, runs great except when it hits exactly 5000rpm - it's as if the ignition key was turned off. No matter the gear it's in, what load/throttle (ie AFM/TPS), quick cycle of the key while in gear and it starts and runs as normal. Even does it in neutral.

    CPS checks out (owner installed a new one just before the head rebuild), sensors all check out - it's unusual for something like this to stump me, but this one has me.

    I did not drive the car past 5k when test driving when it came in, so unsure if it's related to the upgrades.