96 Merc 200 Efi warning alarm issues

[adrunkntoddy]

I've checked this forum, as well as our competitors. 96 Merc 200 efi. Beep beep beep. Runs very rich. Our scanning software gives us tps and coolant temp faults. The values for those sensors are 7.81v on tps and 190 degrees temp. These values will not change, no matter actual throttle position or actual temp. Swapped out tps and temp sensor, no change. Still runs rich and alarm will not go off. No water in gas, or red light on motor that indicates water. We know it's getting oil, runs rich. Is engine in limp mode? Any ideas why temp and voltage won't change and anything else to test? Thank you in advance!

 

[Faztbullet]

Is it a constant beep,beep beep beep when running?

 

[Old Ironmaker]

I know that there are 3 alarms on my 95' Mariner, basically a Merc, non EFI. 1 alarm for cooling water flow loss, 1 for oil delivery problem and a 3rd alarm indicating that one of the other 2 alarms are not functioning. I got a continual alarm one spring and it was #3. Drove me nuts because I knew I had water cooling and oil injection. Good system. You may be getting the 3rd alarm if your EFI has that system. I know more than a few guys that have disconnected all 3 alarms, silly boys.

 

[Dukedog]

Old Iron, don't know where ya got that alarm stuff... there is no alarm to tell ya tha alarms are broken!.. only two on carb motor.. one for oiler stuff thru module (+ one for water in tha fuel on efi's thru oiler module) and one for over heat.. oiler and over heat are two "different circuits" that jus happen to share tha same buzzer... all oiler sensors (+ tha one water in fuel) go thru tha module which makes tha signal oscillate and give tha "self check beeps" when key is turned on...... there are only two oil related and one water in tha fuel sensor goin thru tha module.... sometimes tha module itself will cause tha alarms to act outta whack....

if ya can't get tha tps to adjust to spec, either bad tps, bad tps harness or bad meter...... 7+ volts on tha tps will make it so rich i'm surprised it will even idle...

when you say temp sensor, which one are you talkin' about?

sorry, there is "NO" limp mode.....

 

[Old Ironmaker]

I was told that by one of the most knowledgeable marine mechanics I have ever met. He is 3rd generation running this Merc dealership. I may have misunderstood him but his explanation was fairly simple for my electronically challenged brain. I will ask him again when I see him. Mine is a 115HP 4 cyl. 95 Mariner carbed 2 stroke. I may very well be mistaken. Internet advice is worth as paid for often.

 

[Faztbullet]

Your 115 has low oil alarm,overheat alarm and does not have a delivery alarm as no sensor on pump. It does have a alarm module that fails pretty often on these I4 engines.....

 

[Dukedog]

old iron, I understand.. there is a lot of "lost in translation" that goes around on tha net.. I will add also that my expertise only applies to tha V6 merc/mariner from 1976 up.. nothin' else..