V-Drive throttle

[Rupp]

I have a 2006 Sundancer 320 with twin Mercruiser 350 MPI V-Drives. I have had her out about 8 times this year with no issues. Today, I went out, and as I was accelerating to plane, the port engine seemed to stop responding at 2900 RPMs. The port and starboard throttle usually run even. I continued to accelerate, and the starboard engine came up to 3900 RPM at about its normal position, with the port throttle right with it but the port engine was only at 2900 RPM. I continued accelerating the port engine, and in the last 1/4 amount of space the engine came up to 3900 as well but was bottomed out.

We got to our destination, and I checked the throttle cables at the engine, and they appeared fine. Nothing loose and the adjustments were the same for both engines. I had someone move the throttles, and they moved the throttle body exactly the same on both engines. I then started the engines and accelerated them in neutral, and they accelerated uniformly to 3200 RPM. It appears the problem is only when I am in gear. I did not remove the cover on the throttles at the helm.I also have no codes for the TPS.

 

[dtfeld]

Did the engine actually stop at 2900 rpm and did the boat want to turn to port requiring some steering wheel input? Trying to eliminate tach/insstrument issues which Sea Ray tachs are notorious for.

 

[Rupp]

It did not stop, stall or sputter at all. Had to correct steering.

 

[dtfeld]

It did not stop, stall or sputter at all. Had to correct steering.

Should have been more precise...engine stopped responding/RPM did not increase, but you did feel the boat turning and corrected the steering, so engine stopped accelerating for sure.

Fuel related possibly? Maybe fuel filters dirty small bit of water??

 

[Rupp]

Should have been more precise...engine stopped responding/RPM did not increase, but you did feel the boat turning and corrected the steering, so engine stopped accelerating for sure.

Fuel related possibly? Maybe fuel filters dirty small bit of water??

The mechanic at the marina thought fuel problem as well. He believes it is related to the fuel cooler. From 05-07 mercruiser painted the inside of the coolers. This clogged the fuel pressure sensor and possible the injectors. I am working with them now to replace the fuel coolers and injectors. The service manager said he has had some luck getting Mercruiser to supply the parts. We shall see.