rpm reduction? please help...
hey gents: first time, long time. i am a new owner but have been reading on the site for awhile. i want to get all the details in, so sorry for the lengthy post. I NEED HELP!
i have a 2000 ps190 that i got in Oct of '07. It had 115 hours on the LTR engine. I had it in the water once just after buying it before we had it winterized. During that initial outing after about 10 minutes of running great the boat had a sudden drop in engine RPM and my temp gauge stopped working. I called our mechanic (mastercraft certified) and he said it was likely a problem with insufficient grounding which he would beef up when he de-winterized the boat - not to worry. the boat still has the same problem now after the grounding re-do, minus the gauge glitches. the mechanic and i went out on the boat together and it did the same thing plus the engine had a 'lean pop' so his next thought was insufficient fuel delivery. we replaced the fuel pump and the problem persisted - so now i have a spare fuel pump. the boat has new spark plugs.
the engine runs like a charm so i believe it is an electrical issue as opposed to mechanical. like i said it runs for about 10-15 minutes from cold then the rpm's drop off. the only way to get it to run normal again is to turn it off and back on...each time it runs for a shorter period before rpm reduction.
my mechanic's next idea is to ohm test each electrical connection in the wiring harness and/or borrow another MC owner's ECM to see if there is a problem with ours.
does this sound familiar to anyone? any help or ideas would be greatly appreciated.