Leon Pugh leon.pugh@comcast.net 916 813 0321
02 225 optimax SN 0t469064
Hope to hear from Don on this one
02 Bass Cat Cougar 73 mph @ 5700 with a 26 Fury normal load when cool, 70 latter in the day with full livewells
Severe bog on hole shot, does not feel like a misfire, runs smooth, just feel like to much prop that is not vented. Only happens above about 80 deg air temp and 65 deg water temp. Great hole shot when cooler. Problem is worse after hot soak. Also has a minor surge at fast idle in gear 12 to 2200 rpm only when warmed up
Top end is fine, very smooth idle
405 hours since power head and lower units were replaced
recent: spark plugs correct OE replacements, Fuel filter, compressor filter, two new injectors, inspected and cleaned out vst
87 octane fuel and premium plus oil with quick clean allways
Old plugs looked very good except for minor oil/fuel fouling on #two
Compression variation within 5 psi
When I got this boat 2 years ago it had a fuel gauge issue and power got applied to the sending unit. Some how this overloaded the sensor ground circuit (black/orange wire) causing it to open circuit in the computer thus the computer received maximum voltage signals form all sensor using this isolated ground,
The quick temporary repair was to jump this wire to engine block to supply a ground. As expected there were a few minor issues as result. Yes I do understand filtered isolated circuits and how it relates to voltage seen at the computer.
This current problem just started recently and is getting worse as the ambient temps increase.
Verified no spark degradation while problem was occurring
low pressure pump has 25 psi HP running 93psi Air 83psi
no air bubbles at fuel test port hot or cold
Fuel pressure holds steady for at least 10 minutes after shut down at 25 psi, drops instantly to that value when shut off
I removed fuel rails and connected to a automotive injector cleaning machine (motorvac). No leak down at all during 1 hour leak test
I measured relative injector flow and found #3 and 5 were 10% lower than the rest. Cleaned injectors and there was no change. Those to injectors were replaced
Results were a smoother idle and a little better throttle response
Used a lab scope to verifie TPS is good, range tested map sensor, ats and cts
I replaced the computer with a used one and removed the ground wire. Started fine and ran well on the muffs. Went back to start it a half hour later, went 2500 rpm, constant alarm and over rev displayed. Guess WHAT..... open circuit in computer for sensor grounds
Any thoughts or advice would be appreciated, I am not looking forward amp flow testing every black/orange wire in the system
Got find the culprit before it gets another computer
Can this circuit be repaired????
Thanks to all Leon Pugh