98 Evinrude Check Engine Warning light

[Madaticmj]

Hi:
My engine (twin engines) Model is E150EXECD, 1998 150 HP 60 deg. Last September I had a problem with one engine. While running at medium speed, the "check engine" warning light came on. About 30 seconds later the "no oil" warning light came on. This was major to me. I immediately stopped that engine and returned to port on the other engine. After a short debug period, I found the oil line had separated from the engine at the front connection. It got caught in the steering arm and came off. I fixed this and had no problems for two months. Recently( Nov 26), I was fishing (trolling) at low speed. If the engine was at idle speed (800 RPM) the "check engine" light would come on. At 1000 RPM and above it would go out. No other indication of problems. One other note, the air temp was about 40 deg.
From looking at the engine it appears that the Check engine light is monitoring the vacuum pressure in the NO 1 cylinder. I have not done a compression check. Any suggestions where to start??


Thanks, Mike

[ChampioNman]

Generally the check engine LED is lit when the vacuum switch senses a fuel restriction on the fuel line. It is "Teed" off the main fuel line and samples fuel flow.Since you are running twins, do you feed off separate tanks or a single tank? Check for a possible leak or a sticky float on the vapor separator tank.

[Madaticmj]

I have one fuel tank. The line is split at the output of the fuel filter.

Yes, I see the connection with the vapor seperator now. I will check the float and connections this weekend. Since this only occurs at low RPM should we suspect the fuel or oil pump. These run off of vaccum preasure?? The cold oil may have been hard to pump.

Mike

[ChampioNman]

Yes the VRO which is the fuel/oil pump is driven by vacuum from the pulse limiter which is on the crank case and then is connected to the bottom side of the pump.