Hey guys, long time reader and learner of this forum. First post, hoping you guys can shed some light on what direction I should trouble shoot next or if I should take the boat in to see if any codes can be pulled.
Any helps is greatly appreciated. Thank you
S# 0T556597
2002 CXXL
Mounted on jack plate
Max RPM 5790
Prop; Mercury Marine Offshore Series 23P
Idle water Pressure 3-4psi WOT 12-14psi
Fuel Pressure at idle 41PSI,
Analog Instruments & Vessel Mobile View
I do NOT have a DDT
Issue is constant beep of alarm and guardian mode with RPM reduction to 1800-2000RPM. Once I bring the throttle back to clutch alarm and Gmode go away immediately. Issue first arose 11/11/22 when I was testing the new hi pressure fuel pump I had installed out on the water. OEM fuel pump works great and engine starts, idle and comes up to speed really well. Just get the continuous alarm in the upper 3K rpm range. Got the alarm and Gmode when I was on plane so idled back to the ramp and headed home for some forum reading and testing.
Vessel Mobile View shows engine is not overheating, sitting at 125-132F, verified with infrared heatgun.
Port Bank digital temp sensor 3.73k Ohm at 129F measured off the Tstat housing
Port Bank analog temp sensor 183 Ohm at 130F measured off the Tstat housing
Stbd Bank digital temp sensor 3.5k Ohm at 129F measured off the Tstat housing
Tested boat again in the water
1st test all sensors plugged in alarm and Gmode activated when rpm got to upper 3K range, throttled back down and alarm ceased
2nd test unplugged analog temp sensor (tan wire), alarm and Gmode activated in upper 3K range. throttled back down and alarm ceased
3rd test plug analog sensor back in and disconnect port bank digital temp sensor, alarm and GM activated at upper 3k rpm range. throttled back down and alarm ceased
4th test plug port bank digital sensor in and disconnect stbd bank digital sensor, alarm and GM activated upper 3K range. throttled back down and alarm ceased
5th test unplug all 3 heat sensors, Vessel mobile view showed engine temp of 34F, alarm and GM activated upper 3k range. throttled back down and alarm ceased
6th test plug temp sensors back in and unplugged oil reservoir float switch (blue wires with blue tracer), alarm and GM activated at upper 3K range. throttled back down and alarm ceased
7th test Plug oil tank float switch back in. Rev in neutral to upper 3K RPM alarm and GM activated. throttled back down and alarm ceased
Tested Crank shaft position sensor (358.6ohm) when i got back to the house.
Motors both have their own fuel pick ups and lines from one fuel tank. I Just had the VST apart and it was still clean and nothing offensive in the fuel/water separator.