VP D2-40B Engine Start Problems

[christianbarner]

I've got a Volvo Penta D2-40 in a 2007 Tartan 3700 and we have occasionally had a problem of going to start the engine and the EVC head unit would shut itself off rather than firing the engine when I pushed the start button. This was rare and in fact I worked with one of my yard mechanics and wasn’t able to reproduce the problem in a dozen starts.

Nevertheless, when we went to fire up yesterday, in 15 start attempts, I couldn’t get it to fire the engine. Each time, the EVC just shut itself off. In trouble shooting I noticed a couple of odd things. One was that despite the starter battery being up around 13v the voltage at the starter seemed low and oddly there was 11.5v there as soon as I powered on the EVC head unit. It seems like voltage shouldn’t be there until the starter button is pushed and it also seems like the voltage ought to be a lot closer to the start battery voltage given that it’s three feet away.

I ended up jumping the engine mechanically on the solenoid. Once I did this though the EVC head unit wouldn’t power at all. Eventually, I pulled the fuse in the MDI Black Box which is the mechanical diesel interface and when I replaced that fuse, it powered up normally – and I was again able to start the engine electronically. I thought maybe the fuse was not seating properly or that in fact the MDI box itself was failing. No further start problems last night.

Unfortunately, this morning I went to fire up the engine and depart only to find exactly the same problem. The EVC powers but as soon as I hit the start button, I hear a click and it goes off. Moreover, it causes not just the chart plotter to power cycle, but the radio turns off as well despite having replaced the master and at least in theory fully isolating the house and start batteries. I tried rocking the fuse and eventually even replaced the fuse with a new one -- still nothing. I'm thinking maybe something is grounding out somewhere. Although, it did seem like the culprit yesterday was related to the MDI box. An online search indicates that Volvo has myriad failures of the black box and even has a recall out on the boxes -- although apparently not for my specific engine.

I know many have had to repeatedly replace these boxes, but can anyone suggest any trouble shooting I might try while I'm stranded here on my mooring? Thanks for any advice you might offer.

[SV_FlyingTigress]

Too bad nobody responded. So, six years after your post. I got a completely new cabled control unit from acdcmarine (DOT COM) and ditched the crap Volvo controls and MDI box. They will sell you an engine harness octopus as well, so it makes the installation a bit easier, but plan on about 2-3 days ripping and replacing. Som of their documentation didn't match the wire colors on the loom I received and we had to empirically figure some stuff out.

[christianbarner]

Wow, thanks for the reply -- even if a little down the road. I did finally figure out what was causing the problem. It turned out to be a loose connection on the negative bus bar that only infrequently caused the issue. That said, I've still got the Volvo MDI box and recognize that it is a common failure point. So I'm very happy to have a link to an alternative. Cheers.