Volvo MDI Bypass

[Ian_Rob]

Has anybody on the forum fitted a starter bypass to the MDI of their Volvo D1/D2 series engines?

I was speaking to an engineer on Friday and understand from him that the Volvo MDI is known to be a bit flakey and can fail unexpectedly at any time, making it impossible to quickly start the engine in an emergency. This online article discusses the issue.

MDI box by-pass – www.sy8.nl

Also this : Engine Reliability: A Look at the Volvo Penta MDI Black Box | Nordkyn Design

 

[jlavery]

I fitted a bypass using one of these key switches. Gives the option of using pre heat too.

I connected it to the appropriate terminals on the MDI box to energise the pre heat and starter- so doing what the box was doing internally.

Works a treat - hardest thing was deciding where to mount it. I ended up putting it in the engine bay aft near the saildrive.

I think our MDI is too old to have the reliability problem, seems it's units in a series of production runs/design mods which are susceptible. (Wait for thread drift on this!)

 

[Ian_Rob]

I fitted a bypass using one of these key switches. Gives the option of using pre heat too.

I connected it to the appropriate terminals on the MDI box to energise the pre heat and starter- so doing what the box was doing internally.

Works a treat - hardest thing was deciding where to mount it. I ended up putting it in the engine bay aft near the saildrive.

I think our MDI is too old to have the reliability problem, seems it's units in a series of production runs/design mods which are susceptible. (Wait for thread drift on this!)

I was thinking that a key switch would be a better solution than a button that might be accidentally pressed when working on the engine and this looks ideal. Are there any downsides to the installation ? The articles suggests that the battery charging will not work? Anything else? How old is your MDI?

 

[Beneteau381]

Has anybody on the forum fitted a starter bypass to the MDI of their Volvo D1/D2 series engines?

I was speaking to an engineer on Friday and understand from him that the Volvo MDI is known to be a bit flakey and can fail unexpectedly at any time, making it impossible to quickly start the engine in an emergency. This online article discusses the issue.

MDI box by-pass – www.sy8.nl

Also this : Engine Reliability: A Look at the Volvo Penta MDI Black Box | Nordkyn Design

I got involved with this pre Covid, the latest issue box has fixed it, it seems that voltage fly back from collapsing voltages in solenoid coils was destroying the chips, The boxes themselves are nothing special and DONT control the injection system, as the Iberia VP manager told the owner I was helping! They are basically the same sort of thing as the relay system on the MD 22 and 20X0 series with the addition of some electrickery to convert engine data to nmea2000, so a simple switch/s to the starter solenoid, stop and preheat will bypass it.

 

[jlavery]

I haven't found any downsides.

Battery charging is fine - the alternator connections are (if I remember correctly) separate to the MDI. At least mine charges fine after a manual start.

Obviously then need to shut engine off using manual fuel shut off next to governor.

My engine's a 2011 D1-30, it's got around 3500 hours on the MDI, so reckon it's the original. It's a reconditioned engine I had fitted last year.

 

[jlavery]

it seems that voltage fly back from collapsing voltages in solenoid coils was destroying the chips

Yes, that's one cause I'd read in one of the many discussions.

 

[Beneteau381]

Yes, that's one cause I'd read in one of the many discussions.

The temporary fix in the Ovni that I was involved in was to fit a diode across the offending solenoid.

 

[Beneteau381]

Has anybody on the forum fitted a starter bypass to the MDI of their Volvo D1/D2 series engines?

I was speaking to an engineer on Friday and understand from him that the Volvo MDI is known to be a bit flakey and can fail unexpectedly at any time, making it impossible to quickly start the engine in an emergency. This online article discusses the issue.

MDI box by-pass – www.sy8.nl

Also this : Engine Reliability: A Look at the Volvo Penta MDI Black Box | Nordkyn Design

PM me with an email address and I will send you some stuff

 

[Tranona]

By passes were all the rage in the 2013-2015 period when the units were failing. Mostly to do with heat and vibration breaking down the internal connections. One alternative was to move the box off the engine. However it is now really a non issue as most of the dodgy units were replaced under warranty or a recall (mine was a 2015 and subject to recall - replaced free by Volvo dealer). Units made subsequent to that seem to be reliable. Not the greatest of designs, but tens of thousands in use! BTW it is only non starting that was an issue, stopping can be done manually, although some owners got scared and had not seen the big yellow lever on the fuel pump that says STOP.

 

[Ian_Rob]

By passes were all the rage in the 2013-2015 period when the units were failing. Mostly to do with heat and vibration breaking down the internal connections. One alternative was to move the box off the engine. However it is now really a non issue as most of the dodgy units were replaced under warranty or a recall (mine was a 2015 and subject to recall - replaced free by Volvo dealer). Units made subsequent to that seem to be reliable. Not the greatest of designs, but tens of thousands in use! BTW it is only non starting that was an issue, stopping can be done manually, although some owners got scared and had not seen the big yellow lever on the fuel pump that says STOP.

Thanks - good to know. Our D1-30B started on the first attempt when we relaunched on Thursday but before going out to our swinging mooring, we stopped to fill up with water and couldn‘t get the engine going after that. The engineer now thinks that it is the starter motor but his comments re the unreliability of the MDI got me thinking of what we do in an emergency if it failed.

 

[billyfish]

Very interested in this thread, so had a look at mine today to get some numbers off it and it appears to be different from the photos posted on here mine looks like this, any one got any idea if this is a mod. Should I move it from the block.

 

[Slowtack]

I put in two starter switches.. One for glow plugs and one for starter motor... Since then the latest (4th) MDI box has behaved perfectly...

 

[billyfish]

I got involved with this pre Covid, the latest issue box has fixed it, it seems that voltage fly back from collapsing voltages in solenoid coils was destroying the chips, The boxes themselves are nothing special and DONT control the injection system, as the Iberia VP manager told the owner I was helping! They are basically the same sort of thing as the relay system on the MD 22 and 20X0 series with the addition of some electrickery to convert engine data to nmea2000, so a simple switch/s to the starter solenoid, stop and preheat will bypass it.

Hi did you see the photo and question i posted