Volvo Penta TAMD 74P EDC Long Delay in Engaging

[PNGTaubada]

Hi Carver owners,

I have a 2002 466MY with twin Volvo TAMD 74P-As - although the blocks say TAMD75P - can't work that one out since a serialisation search confirms they are 74P-As. Anyway, these have an EDC system installed.

I had a mechanic fix a problem with the starboard forward not engaging. Dammit he showed me how he fixed this but I cannot recall exactly what he did. My problem now though is that the port forward thrust is taking 30 seconds or so before it engages.

Would anyone have a clue on how I can fix this? Port astern and the starboard ahead and astern thrusts have the normal one second delay before engaging the props.

Unfortunately where the vessel is now there are no VP certified mechanics. So any help or a point in the right direction would be well received.

Raymond

[Lyndon670]

The timing on the EDC control can be adjusted, but 30 seconds is telling me that something else is wrong. Is it truly 30 seconds or does it "feel" like 30 seconds?

The solenoid (actuator) on the transmission could be bad - I would consider switching the port solenoid to the starboard solenoid and seeing if the problem migrates as well.

The other thing to check - the transmission fluid. Being hydraulic, if it is low(er) on fluid it will take longer for the pressure to build - hence longer to move.

[PNGTaubada]

Hi and thank you for your advice Lyndon,

It was truly 30 seconds. But I was also having a problem following the instructions in the manual to re-calibrate the EDC; very ambiguous reading. Anyway I managed to get a hold of another manual which I followed and successfully re-calibrated. This didn't fix it but reduced the delay from 30 seconds down to about 8 seconds. The port-astern and starboard thrusts have the normal one second delay. EDC error reading is 1.1 which is okay.

How exactly do you adjust the timing on the EDC control? I tried to find this in the manual to no avail.

Many thanks, Raymond

[Lyndon670]

I think I have the instructions somewhere in my office Raymond let me see if I can dig them up. I believe there are set screws on the potentiometer in the base that can be adjusted.

[PNGTaubada]

Ahh, this must be what the mechanic adjusted last time. If you could let me know that would be awesome. Also where the potentiometer is located as I tried to find where he did this but couldn't locate. I note that I have the same engines that you have. Best regards, Raymond

[PNGTaubada]

Hi Lyndon, found the problem - thanks for your help

[deenbob1]

Can you tell us what you found and how you fixed your problem? Everyone learns when we share our problems and solutions.

Always include pictures if possible. They really help!

[PNGTaubada]

Hi and yes,

There was a leak in the transmission oil cooler but I didn't detect it at first because it was small, but eventually I found a build up of oil in the bilge. I checked the transmission oil dip stick and sure enough it was low. After getting the water cooler fixed by a radiator expert, I topped up the transmission oil and all was sweet. Bottom line is that the transmission does not engage with low oil or with low oil pressure.

Cheers, Raymond

Oil Leak.jpg

[Seaquestered]

Hi Lyndon, I'm seeing about a 1.5 - 2 sec delay when I shift gears. I've also heard there is some adjustment settings, but so far I can't find anything. Do you still have the instructions or a link that has it posted somewhere? I would like to have more immediate response.

Thanks

[Lyndon670]

I never did dig them up as I though you had fixed the problem. I will dig them up for you next weekend as I'll be up at my boat.

That being said - 1.5 seconds is perfect. You won't get much better than that, as that is exactly what mine is.