Trip Computer without OBD port

[PeeBee]

I would like to have a fuel consumption display in L/100klm on my dash in my 1997 GQ Patrol diesel. I am unsure but don't think this vehicle is fitted with the OBD diagnostic port - is this correct? I am waiting for the vehicle to return from an engine conversion and cannot go out and check. If it does then its an off the shelf purchase I guess.

I have looked at the use of a differential flowmeter to measure supply and return fuel rates to the engine and tank however I expect I either need a link of some description to a GPS or the speedo to get a feedback signal on distance travelled. I have had an Autron Cruise control fitted also, so maybe this would help with a signal? I do have a GPS readout via the CODAN HF radio and also the Hema Navigator however am unsure if I can access this information in some way - probably going to need some comparator box or little PLC perhaps? I am trying to piece this together but don't have the expertise frankly - so electrical wizards please step forward!

thanks
Phil

[NissanGQ4.2]

It will have some sort of diagnostic port Phil,

Taking a wild guess it would be an OBDII plug but using the nissan consult protocol.

And from what I have read if your diesel is injected via the diesel pump then the ECU is unaware of how much fuel is going in so you won't get the information your after anyway.

Sorry I can't help, let us know how you go with it

Cheers

Toddie

[PeeBee]

It will have some sort of diagnostic port Phil,

Taking a wild guess it would be an OBDII plug but using the nissan consult protocol.

And from what I have read if your diesel is injected via the diesel pump then the ECU is unaware of how much fuel is going in so you won't get the information your after anyway.

Sorry I can't help, let us know how you go with it

Cheers

Toddiethanks toddie, the more I look at this the more I see I need a vehicle with greater electronic control to get the data, however the chev diesel v8 I have fitted is deliberately supplied with a mechanical fuel injection control so I don' have the 'black' boxes to contend with. I suspect this is a pipe dream but will chase it a bit further.

[NissanGQ4.2]

I suspect this is a pipe dream but will chase it a bit further.

Anything is possible, just a matter of how deep your wallet is :)

[PeeBee]

Anything is possible, just a matter of how deep your wallet is :)

OK, can we explore the limitless budget train of thought so I can get aligned with how this could be done - any thoughts?

[the evil twin]

Distance travelled - I would use the VSS signal from the speed sensor sama sama like the cruise control.
GPS will be a bit problematic I reckon as you will need to get the data from the NMEA protocol.

Fuel used/flow - you will need two flowmeters, one on the pump supply and one on the return to get the fuel used number.
Here is a link to a bit of a chat about what you may need - http://ecomodder.com/forum/showthread.php/diesel-flow-meters-27775.html
For your research try searching for discussions on fuel figures for stationary engines such as Diesel Genny's etc.

Integrating Distance versus Fuel used - should be reasonably acheivable with an LCD display driven off a microprocessor or cheap PLC

[PeeBee]

Distance travelled - I would use the VSS signal from the speed sensor sama sama like the cruise control.
GPS will be a bit problematic I reckon as you will need to get the data from the NMEA protocol.

Fuel used/flow - you will need two flowmeters, one on the pump supply and one on the return to get the fuel used number.
Here is a link to a bit of a chat about what you may need - http://ecomodder.com/forum/showthread.php/diesel-flow-meters-27775.html
For your research try searching for discussions on fuel figures for stationary engines such as Diesel Genny's etc.

Integrating Distance versus Fuel used - should be reasonably acheivable with an LCD display driven off a microprocessor or cheap PLC

Thanks ET, thats a great start. I had a quick glance at the links and then the embedded links - info everywhere. i will let the forum how this pans out.
Phil