# Fuel efficiency and MAF



## Stevie135 (Mar 24, 2016)

Dear All


I've had an issue recently with my 2005 Swift Freestyle (630L).


My MPG has dropped significantly from around 24mpg to circa 18mpg. I have a turbo tuning device (fitted by previous owner) and suspected this however after running some tests suggested by the manufacturer it would suggest this is OK.


During discussions with said manufacturer, they suggested a dirty or poorly functioning MAF sensor. Great thinks I - whiz it off clean or replace, jobs a goodun.... but problem!! The engine is a 2.8JTD Ducato, but the MAF isn't where it should be on the engine side of the ait filter. There doesn't seem to be one anywhere on the air intake lines. There is however a tube device fitted exactly where I would have expected the MAF. This has some sort of diaphragm and spring attached to it. Could it be that I don't have a MAF and this is some sort of mechanical equivalent? I can trace the tube connected to this to some sort of box - a tube leading from this appears to go to the oil filter??


Also I noticed when I stripped the air filter out that there is either diesel or oil in the pipework leading to the engine - and lots in the previously described diaphragm set-up.


Can anyone please shed any light on any of this? I'm really struggling to find info online and couldn't see anything similar in other posts.


Many thanks for any help.


Steve


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## Mrplodd (Mar 4, 2008)

A turbo-charger is a purely mechanical device, there is nothing to tune. 

If it’s a plug in device it is an electronic gizmo that sends incorrect information the ECU so that it delivers extra fuel (to give a bit more power) If that’s gone on the blink it could be your problem, try disconnecting it to see if it makes any difference.

The bit you are describing sounds like it could be the Exhaust Gas Recirculating (EGR) valve. They are notorious for causing problems. Mr Google will throw up loads of info.

Andy


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## Gretchibald (Jul 22, 2011)

https://www.fiatforum.com/ducato/454967-where-maf-map-sensor.html


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## Pudsey_Bear (Sep 25, 2008)

I wonder if this tuning device is to do with the waste gate or the turbo pressure?

I have the same engine 2002, and get a engine light come on if I go over certain revs under load, I back off and it's fine again, I was told this is the MAP or MAP, just not got around to sorting it yet, it's only been doing it for two years


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