How does Gaurdian act?
 

So I can not find a good description of how Guardian acts when it trips. How does the motor sound, I know you will get beeps but how does the motor act and sound?

It slips, kind of like a clutch, but you`ll never be able to tell. Testing shows the the torque limiting event is 0.095 seconds long. You`ll never know its happening. Thats the beauty of the Drive Guardian! :D

Send me your email if you`d like the tech brief.

He's not asking about Drive Guardian.

Guardian Mercury Fault electronically restricts power. You will not get full RPMs, and overall the motor will feel slow & sluggish.

Yes not the drive Guardian. I have a constant warning beep and I cant get past 1000 rpm. It acts like its going to die, coughing or flooding kind of thing and as soon as I bring it back it is fine. I know when I have hit the rev limiter in other boats it just like shut off for a second, and in cars the same kind of thing. I just wondered what you would hear from the motor or notice if it was restricting you besides lack of power.

Guardian mode limits the amount of rpms - depending on the ACTIVE FAULT the motor can have 5 % to 90 % available power. Again if your motor is limited on rpms and can not reach max full throttle along with a beeps or a continuous warning horn / beeps, you are in guardian mode of some form because you have an active fault (s).

Do not take this wrong but you are beating yourself up over this. I posted again some info and you need to change your water pressure sensor and read some of the other info posted that might come into play. It might be worth taking your boat in to a mercruiser shop that works a lot 496's. Just saying.

Thanks BUP, I did purchase a pressure sensor. I am just trying to understand it all.

Does the beeper sound before anything else happens as a warning or does the beeper and guardian mode come into play at the same time. I routinely bump the rev beeper when running light but have never noticed the power back off. (Mine's a 525)

I hit send too soon on the last one. I am taking it all in thanks for all the advice just trying to figure it out. I only have a problem easing past 1000 RPM under load it stumble some will not let me go any higher. Revs fine in neutral no problems and I can go from idle to wide-open throttle without any problems either boat runs fine until backdown get close to idle again it starts to stumble and act funny. I get no warning beeps until I ease past 1000 RPM.

I would think if I had a blocked pressure sensor or pressure problem I would have that in both idle, neutral rev and wide-open throttle. The same with the IAC in my mind. The other where thing is that all goes away after a while I can Putz around at 1000, get into it hard so it won't do and eventually it stops doing it.

again sorry for all the posts just trying to figure it out. I want to head the lake with everything I got ready to go to leave no stone unturned before I head out there

All fixed it was the pressure sendor as Diacom said it was. Thanks for all the info and help. I also now know what Gaurdian act like when it happens. We were able to get it to do full Gaurdian (only idle) and after cleaning and checking connections (before just replacing the sensor) got a 90% power with two beeps. I am much more informed now thanks again.

Hey thanks for re posting the fix and in the other thread. I figure if people post possible problem solving fixes then the OP can comeback up and post the exact fix when it takes place so everyone can learn.

Like I said no offense, you were beating yourself up and change the water pressure sensor for starters.

These threads are why I return to OSO a few times a week to learn some of the fixes that I might hae to attend to in the future . Nice one guys..

A 100% rule of thumb is with computer control engines and current diagnostic equipment that tests running available power. if your in depth scan shows 100% available power, this will verify that engine guardian is not responsible for reduction in RPMs.

The ECM / PCM system monitors the sensors on the engine, if a malfunction is found the computer system stores a fault, depending on the fault, available power may be reduced as the engine guardian will be activated.

At what point does the warning buzzer sound? At the onset of power reduction or just before? (for rev limiter)

Does not having the trim limit switch hooked up to the boat cause low rpm ? I have a whipple 496 that will not run past 5100 rpm seems to fall on its face at 5000 my scan tool does not show reduced power . Does the computer net to see the trim limit switch?

rev limiter shuts down spark. persay rev limit really has nothing to do with warning horn but it does with overspeed fault. this can set codes along with warning horns - the overspeeds will show in the scan but the warning horn will stop once rpm's are back in specs.

Warning horns come into play as soon as the computer detects a sensor out of range and or out of spec. basically it warns the persons that a malfunction has taken place and will not protect the engine. as some warning horns are critical so protecting the engine is up to the end user. again as soon the ECM / PCM detects an out of range spec / malfunction the warning horn will sound. Its that fast.

Marine engine manu's list continuous warning horn as a critical fault. Engine damage can take place if continue running.

post 14 more info is needed do you DTS, Do you have smartcraft gauges and of course serial # of your engine. Again all serial #'s determines what you actually have as far as an engine set up including parts that has changed during engine serial # breaks. A 2001 496 is totally different set up compared to 2010 496 just as a 2006 496 is different as well, even mid year engines can have changes incorp into them plus different parts installed. It all goes off of serial #'s, not persay year of boat.

Heres is a prime example is at a certain engine serial # breask even the engine harness was changed from a 10 pin to a 14 pin connector, other things change as well thru serial breaks, ignition coils, fuel set up, emission related parts, fuel filters no shift switch / then a shift switch, even the belt tensioner changed at a certain serial # break and so on.

I have a single 525. I am running without a tach now. When I am running light and in real good conditions I can hit 85+ but I usually reach a point where I get a constant buzzer. I drop the drive a bit to lower the RPMs and the buzzer stops. Oil and engine temps are good. Water flow is good. I don't see how it could be anything but an over rev warning buzzer. People tell me that my boat sounds like it is really revving. You can hear it in this short, crappy video. In normal operating conditions I cannot reach these RPMs and top speed is usually around 83. I am running with the original 496 harness for now. Are you saying that the warning buzzer cannot be due to the RPMs? BTW this video was around 83 and I did not get the buzzer.
https://www.youtube.com/watch?v=kSUWplf6m6A

I do not have smart craft gauges zand I don't know the ser. # it had a whipple on it when I bought it so the cover was gone that had the ser# on it , The boat is a 2004 288 sunsation it has a custom tune from Dustin

Its called overspeed and yes your bumping off the rev limiter. It will show up in a scan of the motor and show as many times as the warning horn has came on and off then back on again in a fault called overspeed. So yes you are hitting your rev limiter in which sets off a continuous warning horn until rpms are decreased..

Usually the rev limiter is set at a max of 150 rpm's over the suggested MAX rpm range from the OEM marine engine manu for stock motors. Your rpm range is 4800 - 5200 so if I remember correctly the rev limiter is set at 5350 or possible 5450 for your app. Anyways to long of a period of overspeed will put the motor in Guardian mode as a protection mode.

I would not keep bumping off the rev limiter for obvious reasons - hard on the valve train, too high rpms possible valve float but more important as many people do not realize is you are dropping ignition spark but the fuel is still being supplied to those cylinders.

Thank you. It is propped to hit the limiter only in perfect conditions. Usually it will not rev that high.