2 Warning Beeps on 496ho???
#12
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Thanks so much for the input guys! I am actually going to run the scanner tomorrow hopefully, but def. before I take it out again in a couple weeks.
And no, it did not go into guardian mode at all.
And no, it did not go into guardian mode at all.
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Well as we can see from the charts below, idle output will give 2 beeps and only limit power to 90%, so it will not be in Guardian Mode nor will it be limited to 4000 rpm. Also idle counts would be monitored at idle, when warm, so 99 would be bad. So discussing what is seen on plane is immaterial.
What you will see in many cases (guess you haven't) is the pressure showing approx. 40 psi with the engine Off, Key on. this will NOT set a code and will set a 2 beep and 90% power, once again, no Guardian mode.
What I was trying to help with (not diagnose) was the next post that he was going to make saying, we scanned it and there were no codes, now what? Check the idle counts at idle, warm. Also check water pressures to see if they change and are reasonable when the engine is running and not.
What you will see in many cases (guess you haven't) is the pressure showing approx. 40 psi with the engine Off, Key on. this will NOT set a code and will set a 2 beep and 90% power, once again, no Guardian mode.
What I was trying to help with (not diagnose) was the next post that he was going to make saying, we scanned it and there were no codes, now what? Check the idle counts at idle, warm. Also check water pressures to see if they change and are reasonable when the engine is running and not.
90% IS guardian mode. And I can assure you that when the IAC starts tripping codes (or sometimes not) it will limit the engine to 4000 because I've personally done this twice. I'm sorry to say that this is living proof. We're not even sure if it is in FACT the IAC but assuming it is.... This would be the FIRST increment in guardian mode by reducing power to 90% available.
Further, the IAC on this engine does not act like most all other efi engines. It has a range of duty cycle but if you ever drive the boat around with the scanner hooked up you will see that there are only about two different ranges.. It's either down in the teens to 20% or it's stuck at 99%. Again, this is how the software in the 555 / 496 configuration is coded. It also does weird things with timing. Finally, regarding what ever you see on plane is irrelevant, that's the quickest way to troubleshoot an IAC particularly on a 496 because it locks your power range. Like you, I was only trying to help by possibly preventing a bunch of people from sending him to the parts store while often times finding out that the new part may not have solved the issue.
Yes, I have seen the water pressure max out to the limit of 43PSI with the key on; engine off. But he never mentioned anything about the water flow so that is still kinda wide open. However, once again, if the sensor reduces power by any percentage, it's one of the several different levels of guardian and if you don't have a scan tool handy, trying to run it at higher rpms will tell you but obviously there is risk to that depending on what the issue is.
ALL of the guardian parameters are not on those sheets specifically. Those look like what came with my SmartCraft Gauge and the options will vary from one engine to another.
Strictly from my experience, it gets dang expensive throwing parts at an engine if you're not totally sure. I haven't had to buy one for a long time but I'd bet that particular IAC has jumped up in price by quite a bit.
Not trying to be a "know-it-all". No hard feelings.
Last edited by SDFever; 05-04-2011 at 11:15 PM. Reason: More info