496ho mag help please!!!
 

Okay iv been working on the boat and trying to sort out the pleblem for a long time. Latest thing I'm trying to come up with is when you turn your key on it does the self check. Then start it and it acts as if you turn the key off and right back on and beenps one time. It's very random and happens quite often but I noticed Saturday if you shut the boat off then turn key back to run real fast, it won't self check and then you can fire it up and it runs like top until you shut it off and try to start back.

Do you have a warning horn hooked up ? If not the PCM does not see it or the other side of the coin is do you have a operating warning horn that goes off with the self check ???

I take it you have smartcraft craft gauges to see the system self checks ??? is this correct your app has smartcraft gauges ?

EC 555 and PCM 555 need to have a operating warning horn

you need to look for a fault of horn output while scanning. if you have that what is it showing ?

I do not have the smart craft gauges.
I just have the warning horn for low pressure and high temp and all that. It beeps on time when I turn the key on and everything just fine like it's always done. But once it's done that and then you start it, it will do it at random just like you turned the key off and right back on without dying, just makes the boat kind of lung forward.
But like I said once running if you turn key to off and then right as it dies take it turn it. Ack to run it won't self check or beep and the boat runs damn good. I'm not real sure how that self check oprerates or what would cause this. Thank you for the reply and for insite you may have to get to the bottom of it

Also not showing any failt codes whatsoever on entire engine

go back in history and look in there for what codes that may have faulted hours ago. The PCM persay controls the system checks / key battery voltage and horn output is also in the mix.

scan tool owners should know and perform this ? output tests - one with the scan tool has the ability to perform many pcm actuators and controls to see if they are correctly operating. The output tests, listing most of them are -- fuel injectors, IAC test, fuel pump relay, warning horn, tach output, ignition coils, plus a few more. The performed tests can determine a problem with what related parts and or related systems.

ALSO when performing the output tests it is called for to unplug the fuel pumps per instructions.

Check your kill switch, especially if you're in salt

I checked for stored faults and the boat doesn't shoq any. Also I ran the troubleshooting test and everything seemed to check out fineness on all test.
Thanks for your reply. I really wish I could get this thing figured out

Hard to find and fix problems like this without hands / eyes and ears on it. You need to take it to someone that works on 496's -- the problem is a lot shops hate 496's. Possible PCM issue or a ground issue and or even possible a 5 V issue.

anyone can throw out whatever - eventually that could be the fix but that could end up a lot parts changing. plus dollars and non use of the boat. .

I would be interested in the fix or possible figuring it out. but really this problem child does not need darts and dart board --- it needs to be looked at, tested and so forth..