2007 Mercury EFI 150 HP Alarm - Any Ideas?

[rkleekamp]

Here's one that stumped even my mechanic -

Got a 2008 Nitro Z7 with a 2007 Merc 150 HP EFI with 70 hours on it. I get a single alarm beep and the engine cycles (shuts off for a split second) while on plane anywhere from 3000 to 5000 rpms. Usually happens once or twice a trip. I keep the oil tank at least 3/4 full, from what I've researched the single beep is related to oil issues. Everything else is fine, my mechanic checked all the connections and sensors and of course when he runs it, its fine.

Has this happened to anyone else?

Thanks to anyone with ideas -

[EuropeanAM]

Welcome to BBC!

Based on your description, I'd suspect one of the following:

-Ignition switch harness plug at engine. This may have been "adapted"- usually the 8-pin cannon plug connector has loose MALE pin connectors. Disconnect, clean pins, SLIGHTLY and CAREFULLY spread the male pins with a small pocketknife. Reconnect and ensure the connector is CLAMPED/STRAPPED in place (so it cannot vibrate and loosen).

-MPR (Main Power Relay)

-Ignition Switch (or connections AT the ignition switch).

I suspect the power is being dropped momentarily... and the "beep" you're hearing is the "test beep" sent by the PCM when it repowers.

One other place to look... main wiring harness at the three connectors for the PCM. In some cases, this harness can RUB against the starter/brackets, resulting in chaffed wiring.

[rkleekamp]

Hey Brother, thanks for the input, I appreciate it, I'll forward this on to my mechanic and will let you know -