2000 Sea Ray Sundeck 210 HELP!

[Lazy Daze]

The tach switch "contacts" can get dirty, leading to a wrong reading. I'm thinking this is "probably" not the RPM issue, but it's a freebie to check it out... just to be sure.

If the gas is bad enough, it is unlikely that Startron (which I DO like - I use it myself regularly) will "rejuvenate" the gas. Smell it and dump into a glass jar. Don't guess - do it.

In newer EFI systems (newer computers), the IAC will sound the warning horn. I'm not sure if it does so with your MEFI-3. Some sensors will, I'm just not sure with this one. See what happens (you won't do any damage) if you disconnect it while the engine is idling (horn and/or dieing).

Could be a loose throttle cable (at engine) causing this, too.

In the end... I think you're probably best getting it checked out by a Merc technician with a CDS scanner.

 

[boater2018]

There has been a few occasions where I have turned the key "on" without starting.....heard the fuel pump and 2 beeps....then turned the key to start and heard another beep, maybe 2....perhaps that's an alarm, but it doesn't happen every time I crank the boat. The switch on the tach is definitely turned to 8 cyl setting, I do know that for sure. I'll have to do some more checking on the other items. I hope I can test the IAC tonight, but we are going out of town this weekend, so we'll see. Got to use the boat this summer though......so frustrated with these local mechanics...I've had to learn to fix the problems they were supposed to! (Frustration)

Thank you for your help on these issues....great forum!

If it had bad gas, wouldn't that cause problems all the time and not just at idle? I assume if the gas ends up being terrible, it would need to be completely replaced?

 

[boater2018]

I think I found the culprit....I took off the IAC, plugged it in, turned the key on...it moved in....turned the key off...it moved out a good bit farther than it moved it....turned the key on again....moved in.....turned off...moved out and the extended piece popped out and in the bottom of my engine compartment. I take this that the IAC is bad. I plan to replace it, crank it up, adjust the idle back down to 600 rpms, and hopefully all will be well.