Volvo Penta engine will not increase revs after engaging forward gear (intermittent)

[Steve S]

Tigerfish is fitted with 2 D4-260 A-B with a DPH drives, approx 980 hours

The port engine intermittently will not increase revs as I push the throttle forward (reverse is fine).

Forward gear is engaged and there is drive at tickover, but trying to increase speed has no effect. If I then select reverse gear for a moment, then forward gear again it was normally ok again, but this is not now doing the trick.

Half way through last trip (fishing on the drift) it would not increase forward speed whatever I could think of doing, so I started to make my way back slowly and then after 10 minutes tried neutral and forward again and it worked!

Just moving the throttle forward with the drive disengaged does increase the engine revs up to 2000 as I think is normal.

As an intermittent fault hard to figure what is going wrong, any ideas?

May not be related but the same engine also intermittently stops once up to normal temperature when taken out of gear.

[crazy fred]

To rule out the throttle control unit out swap the plugs over so port becomes starboard and see if the problem reverts to the other engine . If so new control unit needed .

[Steve S]

Thanks Fred I'll try that

[Steve S]

Thought I would post that the problem is now fixed. The guys at Ropewalk thought it was a sticky gear selector cable. I found that surprising given the symptoms, anyway, I let them go change it which they managed without putting the boat on the hard by doing some of the work attaching the cable to the leg underwater from the swim platform, impressive and saved me a haul out charge.

 

Anyway after a month of use and many many gear selections/de-selections all of the faults listed above have disappeared so I think I can say it is sorted.

[Jim]

Nice one Steve.

 

She IS a lovely boat.

 

Jim