Volvo Penta D2 40 Fuel Gauge Swap

[jezzb]

Hello,

My Bavaria 38 from year 2008 came with a Volvo Penta D2 40 engine. The fitted fuel gauge is the one with volvo part number 863940. I would like to swap the current fuel gauge and install the one with volvo part number 874926. The thing is that the 874926 connects directly to the Tachometer (daisy chained to EVC) whilst the one which is currently fitted is wired to the fuel tank sensor.

So my question is - if it is possible to install the part 874926 and also if this is a major job.

Thanks in advance for any replies / suggestions.

BR

Jezz

[DougR]

If your D2-40 engine is equipped with the MDI box and uses the EVC tachometer then you can use the 874926 fuel gauge.

You will need to remove the two wires which run from the tank sender to your existing gauge and connect them to the two push-on connectors found on the bottom of the MDI box. (There are three spade connectors on the bottom of the box, two close together and one seperate. Use the two close together.) Connecting the sender to the MDI box will allow the box to read the resistance value of the sender and convert it to CAN bus language which will be broadcast on the CAN bus. Daisy chain the fuel gauge to the tachometer and you're set to go.

DougR

[jezzb]

Hi DougR,

Thanks for your quick reply and detailed solution - much appreciated. I do have an EVC Tachometer. Please excuse my ignorance, but where is the MDI box normally located ? How does it look like ? Is it the panel with On/Off Start/ Stop Engine Panel or something else please?

Thanks
Jezz

[DougR]

The MDI box, (mechanical diesel interface) is located on the engine, bolted to the side of the heat exchanger/ exhaust manifold. It's a black box about 100mm x 50mm x50mm. It will have three rectangular connectors going into the bottom of it, one from the engine harness, one from the panel, and the other from the multi link harness. There are also three heavier bolt on terminals with wires from the starter, glow plugs and battery.

If memory serves me correctly, there is a basic connection diagram on the label which shows where to hook up the wires from the fuel sender. If you don't see the label, look on the bottom of the box and you will see the three push-on wire connectors. As mentioned, you will use the two connectors that are close together for the fuel sender. The other single connector is for any other alarm you might want to install, such as a "high bilge water" alarm.

Hope this helps.
DougR

[sailingallover]

DougR,
D2 40
I actually just saw this this morning since for the 4th time since 2007 my MDI has gone bad. So I am in the process of removing it as it a dangerous hazard both to me(first time it didnt start was entering Las Palmas when 2 months old) and my wallet.(Volvo part). Along with the engine stop solenoid went bad once again leaving me unable to start for a few weeks.
I have the temperature, motor stop/start replaced but do you know the resistance ranges for the non EVC fuel sender(which I have but Bavarias guage rusted out) and the configuration resitance for the oil sender and the tach. Aftermarket gauge suggestions would be extremely helpful. Thanks!

[DougR]

Hello Sailingallover,

Sorry to hear of the problems you have experienced with the MDI boxes on your D2-40. There were early problems with the boxes but I thought these were resolved with generation 3.
Frequently when an MDI box fails it can take the stop solenoid with it. This happens because the stop solenoid is designed for intermittent duty, usually being activated for only a few seconds at a time. But if the MDI box fails, it can energize the stop solenoid continuously, and this causes the stop solenoid to burn out. Even if the solenoid fails, you can run the engine with just a bit of effort. Disconnect the two wire connector and remove the solenoid from the back of the injection pump. If the solenoid has failed in the "stop" position, the small plunger on the solenoid will be extended about 17 -18 mm. Push the plunger back into the body of the solenoid, and replace the solenoid in the pump, but don't plug in the connector. The engine should now run, but you will have to stop it with the manual stop lever.

The fuel tank sender is the same for the MDI equipped engine as for the standard engine. The normal metric gage sender values are: 10 ohms when empty and 180 ohms when full. A VP gauge will work with this sender, or you could get a VDO or other gauge as long as it is designed to work with this type sender.

The sender values for a metric oil pressure sender are the same 10-180 ohms, where 10 ohms is 0 pressure, but as I recall, the D2-40 is equipped with an oil pressure alarm switch only. There was no gauge sender on the standard engine.

The tachometers on both early non- MDI engines as well as the MDI engines are driven by an inductive pickup which is mounted on the flywheel housing. This pickup contains a magnet and a wire coil and basically counts the number of slots which are machined into the flywheel. Every time a slot moves past the pickup an electric pulse is sent to the tach (or MDI box) and the tach converts the pulses into an RPM reading. You will have to remove the pickup from the flywheel housing and count the number of slots which are machined into the flywheel just below the pickup opening. ( I don't remember how many there are)
Mark one of the slots with a magic marker, and then rotate the engine with a wrench on the crankshaft nut. The number of slots will equal the number of pulses per crankshaft revolution, and you will need that number when sourcing a new tach.

Again, you could get a VP tach from the earlier non- MDI D2-40 engine, or a VDO or other brand tach. If you go other brand, be sure you get a tach that can operate on an inductive sender.

I hope this is helpful.

DougR

[sailingallover]

Thanks so much Doug. There is no way to check the fuel sender without making a mess with the open tank and I could not find how the tach worked at all. Although I am willing to live without one. I will write up and make. A webpage on how I do the final as having to spend $700s every couple years on this is killing me.

[sailingallover]

A VP non MDI tach would be great if I can find one
Any help.with an engine or part number?

[DougR]

The part number for the VP tach is 873992. Along with this you will need a mounting bezel for the face of the tach, 873517 and the metal bracket for the rear of the case, 873208.

This tach is a "universal" tach used for several models, and it will have to be set for the D2-40, but instructions for setting and fine adjustment will be included with the tach. This tach also has a digital hour meter in its face. The face is black and the needle and numbers are white, and it has provision for night lighting.

DougR

[sailingallover]

Doug, You are a god and my hero. That will save me.a days hunting.

If you ever need a favor in the VIs let me know.

[sailingallover]

Doug.. if you are still around.
Overheat sensor the volvo shop gave me a W6972 sensor that screwed into the manifold fine just below the temperature sender. But they really did not know for sure if it was an overheat switch.. can you shed light on this?

[DougR]

Nope.....I'm not familiar with that part number, but it could be a temp alarm switch.

Normally the way these switches work is that they are "open" between the two terminals ( if it has two terminals) or open between the single terminal and the threads when the temperature is normal. Then if the temp gets up to the design alarm temp the switch closes and current can flow in the circuit. This causes the alarm to activate.

You can test this with an ohm meter....at normal temp there will be no continuity between terminals or between the single terminal and ground. If the temp gets too hot you will get continuity. Usually the body of the switch has the temp stamped into it, around 104 or 105 C. This might require a heat gun to test as boiling water might not be hot enough.

DougR

[yobird]

Hello Sailingallover and DougR,
Also replacing the ⚡ dangerous MDI on my D2-55 with old fashion gauges, I am looking for part numbers to use.
Any info appreciated.

Originally Posted by sailingallover

DougR,
D2 40
I actually just saw this this morning since for the 4th time since 2007 my MDI has gone bad. So I am in the process of removing it as it a dangerous hazard both to me(first time it didnt start was entering Las Palmas when 2 months old) and my wallet.(Volvo part). Along with the engine stop solenoid went bad once again leaving me unable to start for a few weeks.
I have the temperature, motor stop/start replaced but do you know the resistance ranges for the non EVC fuel sender(which I have but Bavarias guage rusted out) and the configuration resitance for the oil sender and the tach. Aftermarket gauge suggestions would be extremely helpful. Thanks!

[DougR]

Hello Yobird,
I can’t supply part numbers for you because I am away from my normal source at the moment, but I can maybe give you a little help in finding them.....

I suggest going to one of the online VP parts sources, such as Marine parts Express, or Volvo Penta parts Europe and search under parts for the D2-55C model. The “C” version was the last version before MDI and it has all the senders and switches to drive regular gauges. All of the sender values for the engine are setup for metric gage values, so will drive VP gages, or metric VDO, or any other metric gage.

The C engine was equipped with:
- combination oil sender/ oil alarm switch. Mounted on the stb. Side of the engine at the bottom end of the oil pipe feeding the cylinder head.....same location that your engine uses for its oil alarm switch.
- a water temp sender and a water temp alarm switch. Both mounted in the port side of the heat exchanger tank. If memory serves me the front most was the alarm switch and the one in the middle of the tank was the gage sender.
- tach sender. Mounted in the flywheel housing. Same one as used in your engine. Provides 30 pulses per engine revolution.
- the engine had two relays located in the electrical connection box which was located in the same location as your MDI box. One relay for glowplugs and the other a starter relay. Plus a 15amp fuse to drive the instrument panel...
- the stop solenoid is mounted on the rear of the fuel injection pump, and it was driven directly by the key switch. There was no relay for it.
- the key switch had several positions, and can be easily replaced by buttons...
Off, on, glow plug, start, and stop.

Hopefully this will get you headed in the right direction.

DougR

[yobird]

Thanks Doug R for this great info.
That's a start. I will have to look online for these sensors and gauges.
In the mean time I'm considering keeping and using the original wiring harness and panel and ditch the MDI box, just not sure how.
I don't want to butcher the wiring end plugs in case a future buyer wants to put a MDI back.
Dunno, am I over thinking this guys?

BTW I'm currently in SE FL