Bongo Fury

Hi, I need a bit of help on ideas about low mpg.

Had my 2.5L 2001 V6 Bongo for around 3 months now. Had it serviced, ignition service, new oxygen sensor, new brake discs and pads, and an LPG conversion (BRC).

I’m currently getting a fairly consistent 12mpg on LPG. It’s been back in to be tuned and is running well. The petrol (all though not measured) also disappears quickly.

Any ideas on the culprit? Need to get it sorted before a big trip in June.

All help appreciated.

Welcome aboard!

Not sure if your saying that LPG was 12mpg and now after a service its working better or that its working but still only 12 mpg.
My V6's, not LPG converted, run around 25mpg on good runs and 18mpg around town.

Hi Geoff,

Sorry, it’s still running at 12mpg now. It was actually less before the replaced oxygen sensor.

Any idea what I should have checked out and if there are any common factors in losing that much efficiency?

It’s generally running well and has been checked over generally by 2 garages. It’s not obvious to me as a non mechanic, where to start.

I'm not a mechanic either, give me electrons to play with
But it sounds like its over fueling, however you have seperate controls as I understand it with LPG so it suggests that the LPG controller is having a problem but I guess you also need to know what it is doing on petrol alone, if that is also over fueling then it maybe suggests a common problem ? Are you able to leave it on petrol alone and get an actual measurement of petrol mpg alone ?

Thanks Geoff,

I'm dropping it back in to be re-tuned for the LPG today and if that doesn't do the trick I'll try and get a petrol mpg and go from there.

Cheers.

Well it turns out that the odometer is tracking miles and not km. Therefore I'm getting around 19mpg around town on LPG which is reasonable. The garage did say that the lamba sensor was not functioning properly though as it was reading a single voltage when idling instead of oscillating between 0.1-0.9v.

Can anyone confirm what the voltage readout should be before I pay for a replacement? Also is it necessary to buy the very expensive Bongo specific sensor?

Lastly, now that I know I'm tracking miles instead of km it brings the question as to what the actual mileage of the vehicle is (I was sold it as km). I can get the first MOT mileage and assume that was the km number and it's been accumulating miles on top of that since. Would you say that is a fair assumption?

Again, appreciate the help.

Definitely agree with that, the speedo would have been changed on import.

Hi Bob,

Are you saying that my assumption for the first MOT reading being km and the rest miles is a fair one? I was wondering how often are the odometers manually adjusted when changed to miles. I'm hopeful that isn't the case and the difference is less than 20k miles.

Thanks,

Yes, exactly what you say.

Sadly impossible to know if it’s been 'clocked' but if it was one of the many reputable importers it’s very unlikely.