Arduino Bongo Turbo Diesel ECU

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End of 2019 I picked up a 1992 Mazda Bongo Brawny 4wd camper van, ex japan but been in NZ uncomplied since 2014.  Mighty Mazda R2 non crossflow 2.2 diesel non turbo.

1st drive, its gutless so put a 1kz turbo on it, custom manifold, shit load of work and prob should have pulled engine and put something else in.  At the end of it all, it actually goes ok, have towed jetski to Kaiiwi and back a couple of times, over the Coro hill a few times, been around East Cape.

I made a EGT digital switch that at 630deg pre turbo opens a boost control solenoid and bleeds off boost to the diaphram, drops boost from 9psi to about 4psi and the egt drops down pretty quick to mid to low 500s, with a pretty decent drop in power too, so its best to ride the egt gauge and keep it on the boil around 550 to 580 deg and it will get there just fine.

Plan has been for a while to make a Arduino controller with a screen, sensors for EGT, water temp ( it manages temp pretty good most of time), and maybe boost sensor, and use those inputs to control the boost solenoid with duty cycle on closed loop to actually control egt.

Boost control and EGT gauges are common projects, so i think this is possible.  

Arduino is on the bench, bit to learn and then hopefully make things work.

Video from Japan, 2013ish before it came here.  The roof box must have hit something on the way as the base was in the back still, and the bars had been torn from the roof.

 

 

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Specs on the build so far....

Engine had 32000km on it when came into the country, genuine kms.  Now done 48k or so. Doesnt use a drop of oil it doesnt drip (been chasing that leak for ages)

Diesel pump is off a similar mazda 2.0 turbo diesel, bolt on fit and works well.  Had a lot of fun "tuning" it, quite a cool design.

Turbo manifold is steampipe log style, post turbo is all 2.5" mandrel bent with a single muffler.

Has a chinese water to air intercooler where the airbox used to be under the drivers seat, with a Davies-Craig water pump and heat exchanger in front of radiator.

Had a lot of overheating issues initially, changed all the pump, thermostat, got the radiator flushed and cleaned as its pretty big and thick from stock, had a massive high power elec fan and it just kept cooking itself.  Put a mechanical stock fan back on with a shroud and it now runs around 80 to  90deg all day, except for really wild 2nd gear hills where it gets to high 90s after a while.

Have had the front of the crank break off, mrs was heading to Waihi beach with kids for school hols, died on side of road.  Wasnt happy.  Got a short block bottom end cheap, swapped the crank out, reused the bearings as low km and looked fine, and then a new head as the valves all got smashed from the cam belt drive being part that came off.   Old original crank was a poor design, new one was better at least.

Certification also required driveshaft hoop, rear steel frames to allow for 2 more seatbelts so it can legally sleep 4.  Diesel heater does hot water too.  Homemade lithium battery with 24v 2500w inverter, 300w solar panel, 120amp 2nd alternator to keep charge up while driving.  Run a 200w induction cook top off inverter, works a treat.  Its very compact inside, but main bed in back is pretty much queen size, and kids sleep easy enough over cab space. Also fitted a 130litre fridge.  

 

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 Diesel hot water heater is the one shown in this vid.

If i was doing a purely hot water setup id do it different, maybe a Webasto or something for pure hot water heating and have a separate air heater.  Its a 8kw, and its a bit too powerful for the size of the camper, even on a cold night need to crack a roof vent or it gets a bit toasty. 

Camper had a propane hot water cyl from Japan, as well as a propane 2 burner cook top, but where the bottle used to be ended up being where the rear seat frames needed to go, and carrying a lpg bottle introduces a few other issues. I think it originally had a generator on a slider in the back left corner too. Ive got the diesel hot water plumbed through the original hot water cyl, has some fancy acutated valves so there is no water in the heater when the pump isnt on so doesnt go festering inside the heat exchanger.  Can get cylinder to 60deg in about half an hour, enough to do proper dishes or a quick shower to rinse off. Only has a 85 litre fresh water so showers are brief if need be depending on supply.

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Got the Ardunio plugged into laptop, loaded up the programming software, and can now make a LED blink at various speeds.

Rekon im almost finished!

 

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Pic dump...

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Bit ambitious but got down the motorway at 80ph to VTNZ for a wof on both. Also GV weight what>??

 

Ive given up on the Arduino idea, tried a few things but its either beyond me or not feasible.

I did have a high temp programable switch with a EGT sensor pre turbo, with the relay triggering a normal boost solenoid y on the line to the pump, at 630deg it will turn on the solenoid, and bleed off boost, therefore reducing fuel delivery and lowering egt, but its a bit aggressive and also the triggering temp is a bit random.  

Im surprised no one makes a EGT gauge with this function built in, preferably with a way to say start at 10% duty at 550 deg, and 100% at 630deg or so (Programmable).  Maybe there is a way to do with arduino.