MPGuino for Suzuki Swift Diesel

[archat68]

I'm a noob in the matter but I'm very interested in installing a Mpguino in my Suzuki Swift Diesel. Can it be done? I want to confirm before I invest money

[archat68]

BTW the car is 2008 build, runs a CRDI engine. Has OBDII but the protocol followed by the manufacturer is proprietary and the SGII doesn't works with it.

[dcb]

I'm 99.9999999...% positive it will NOT work on your diesel. That is something we haven't sorted out yet.

[archat68]

Ohh!!
That means there is no instrument that I can use to check the mpg!!

[Ryland]

Originally Posted by archat68

Ohh!!
That means there is no instrument that I can use to check the mpg!!

Other then checking your mileage every time you fill your fuel tank.

Altho your diesel has a common fuel rail with what I assume are electronic injectors, so what is stopping a MPGuino from working?

[archat68]

Originally Posted by Ryland

Altho your diesel has a common fuel rail with what I assume are electronic injectors, so what is stopping a MPGuino from working?

I also thought that it should work. But my experience is limited and I want to be sure before I pour some money.

The confusion is arising because SGII does not work with my vehicle since the OBD is somewhat non-standard. But MPGuino is not related to OBD - so it should work if I can just find the injector and speed signals (Vss), AFAIK which all modern cars have.
Correct me if I'm wrong.

[dcb]

I think there are some reeeely small pulses in there that smooth out power delivery that might get missed by the guino. I don't know for sure that it won't work, just last I looked it seemed like maybe not. I don't recall if it has been tried.

[archat68]

Well I built a MPGuino based on Arduino.
My car has a CRDi engine which is actually a Fiat 1.3 Multijet engine. The injectors have a impedance of 0.2 - 0.5 ohm. Also the brief functioning of the engine from the Fiat site:

While the new Multijet engine is in operation, the control unit continually adjusts injection arrangement and number (as well as the amount of diesel injected). When coolant temperature is lower than 60°C and torque requirement is low, two small and one large injection are performed, very close together. As torque increases, the number of injections drops to two: a small one and a large one. Under conditions of high rpm and high torque demand, only one injection is performed. With coolant temperature over 60°C, things change again and to minimise emissions the injection arrangement becomes: one small, one large, one small.

So, as you guessed - it didn't work when I connected with my car .

When I was going through the service manual of the car I found that the car has a "Accelerator Pedal Position (APP)" sensor. The output voltage of the sensor varies from 0.60 to 4.30V varying according to depressed extent of accelerator pedal (see the attachment).

Can this sensor output be used in anyway in the MPGuino?

[mcmancuso]

the pedal has little to do with fuel used, that sensor functions like the throttle position sensor in a gas car. Its there so the computer knows whether you're pushing the pedal or not, and how far. This does not directly correlate to fuel used (it relatively correlates but that's no good for measurement) since fuel usage is dependent on engine RPM and load (as well as other factors)

[archat68]

Thanks for the clarification.
So, can we use the MAF sensor output (SGII uses this) to calculate the fuel consumption in any way?