Oil injection - sensor and alarm

[dkwestern]

My oil injection alarms are going off on all 3 of my engines, except when I start them they all smoke a bunch so I know they are getting oil. One of my caps on my engine oil tank broke, so i replaced it and they still all beep the alarms. I don't think there is a reset but am I wrong? I might get rid of the whole system and just mix, which would not be bad because I have 2 100 gallon tanks, so I could just mix a gallon of oil at a time with 50 gallons of gas, and keep the tanks 1/2 to 3/4 full. Any input is greatly appreciated. When I run the engines my pyrometers stay right around 1200 so there is no overheating issue either, I guess I just don't get it. Thanks in advance. Darren

[pyro]

The oil injection warning module is checking for two things when the engine is running:

1. There's oil in the tank.

2. The oil pump is rotating.

Check the wires from the oil cap (blue and black?), continuity (zero ohms) means the sensor float is at the bottom indicating "empty", or the sensor is bad. If the reserve oil tank is full, try unplugging the sensor, if the alarm quits, the sensor is bad.

The oil pump shaft has a magnet inside it that triggers the sensor on top of the oil pump (3 wires going into the sensor), if it's getting magnetic pulses, the module stays happy and quiet. If there's no pulses, the alarm will go off. Make sure the sensor is properly connected, if not, the alarm will keep going off.

Also, on Laser EFI motors, there is a water-separating fuel filter.
The filter has a little module hooked to it that triggers the oil warning module if there's water in the filter.

The warning module may also be faulty. Both Merc's I've owned have had this replaced at one time.

[dkwestern]

thanks guru, Maybe I'll pour a little oil in the remote tanks, and check all of the leads and hope that fixes it. Thanks. Darren

[pyro]

Make sure your remote (main) tank has the cap on tight, it relies on pressure to push oil into the reserve tank, (the one on the motor.) The float in the cap is supposed to set off the alarm if the tank is even a few ounces less than full.

[sosmerc]

You would be wise to make it part of your seasonal service to pull the oil pump, replace the bushing and o-ring, remove the plastic bearing and metal shaft so you can do a visual inspection of your plastic drive gear. I put a "bend-a-light" down the hole so that I can look at the gear while turning the flywheel by hand. I look for signs of plastic shavings and thin spots on the gear. Also, check that plastic bearing (that has the motion sensor magnet inside) for galling. You might also consider replacing both of the clear oil supply lines every year.
I have also found that low voltage can trigger your oil alarm...especially during cranking. And a bad switchbox output on the cylinder that the oil warning module is hooked up to (green wire) will trigger the alarm.
If you don't mind mixing your own.....that's really the best solution in my mind. I'm hoping the new electronic oil pumps on the later engines will be an improvement, but I think it is too early to tell.