Check Engine

[RHINGA]

I have a 2000 Johnson 200hp (2 stroke carb) Runs great... But when it is first cranked the check engine light and, very loud, alarm comes on for a few seconds. Alarm noise goes away but the check engine light stays on. From what I can read here, it is a fuel restriction problem. Maybe fuel filter?

 

[Chris1956]

Re: Check Engine

Check engine is a fuel restriction, however, it usually doesn't happen at idle.

Certainly clean the main strainer under the airbox, and change the water seperator if you have one and have not done it recently. Do you get the alarm if you turn on the ign w/o starting the motor? If so, you have bad wiring or bad vacuum sensor.

 

[RHINGA]

Re: Check Engine

Turned on ignition. The "check engine" light is on but no audible.

 

[daselbee]

Re: Check Engine

You should get a very short beep when you turn the key on. The tach lights will "cycle" i.e. light up in sequence and then all go off.
I think chris's answer is very good, you can debug by simply disconnecting the vacuum switch located right next to the OMS fuel pump.
If it still lights, you may have a bad tach.

 

[RHINGA]

Re: Check Engine

Yes, I get the usual short beep then light check. I am going to go out and try disconnecting the switch now. Thanks. Will post what happens.

 

[RHINGA]

Re: Check Engine

OK. Assuming the plug with a black wire and tan (w/orange strip) right below the fuel pump is the vacuum switch, I disconnected it and the light does not come on. The usual check runs with beep and light does not come on.

 

[daselbee]

Re: Check Engine

If you unplug the switch and the problem persists, with the switch unplugged, check the resistance of the tan/orange wire (harness side) to ground. If shorted to ground, the problem may be in the harness, but that is a very rare fault. More likely a stuck closed vacuum switch or a bad tach. Meter debug time.....

 

[RHINGA]

Re: Check Engine

Problem goes away with switch unplugged. Guess I am off to get a new switch. Thanks for your help.

 

[daselbee]

Re: Check Engine

OK. Assuming the plug with a black wire and tan (w/orange strip) right below the fuel pump is the vacuum switch, I disconnected it and the light does not come on. The usual check runs with beep and light does not come on.

Great you found it. Check the switch with an ohmmeter, and you will find it is stuck in the closed position (shorted to ground). It should be open in normal operation. ONly switch to ground if the engine develops a high vacuum condition ion the incoming fuel line.

 

[daselbee]

Re: Check Engine

One other point...the audible alarm will ONLY SOUND when the engine is running. Key on, engine off, the alarm will not sound. Key on, engine on, the alarm sounds for 10 secs, if a fault exists.

I am not talking about the chirp at immediate key on.....I am talking about an operating fault that would trigger the alarm. So, your system is doing exactly what it should, and you have found a defective vacuum switch...

 

[RHINGA]

Re: Check Engine

checked switch - it is in closed position. Thanks again.

 

[RHINGA]

Re: Check Engine

Ok. It took almost two weeks for a new switch to come in. It looks like a pretty easy install, other than the tight fit. Is there anything I should know, other than disconnect wire, remove switch disconnect hose. Then install new switch, connect hose and wires? Is there something this is going to mess up that I don't know about?