GolfGTIforum.co.uk

Model specific boards => Golf mk2 => Topic started by: Procomp on 15 June 2009, 13:07

Title: Dodgy MFA or Poor Fuel Consumption??
Post by: Procomp on 15 June 2009, 13:07
Hi
Looking for some advise from the wise :smiley:

My on board computer is showing I'm getting about 15-6mpg at present.  This is even after I've reset it and drove it gently over a period on a long run in 5th gear on motorway type crusing.  Not yet done the calculation of full tank of fuel v mileage covered; as I've not really had the opportunity to drive the car over a longer distance/period. 

I was wondering if there were any common faults with the MFA's to consider of if there is a set up tuning issue to think about?  The temperature, clock and journey travelled info is spot on on the MFA.

My engine is running fine it appears.  There ar no obvious signs of excessive fuel burning...smoke, smells, etc.  It's been recently serviced, so it has new plugs, leads, dizzy/rota, etc.  I got the car as a non-runner and had to fit a new fuel pump & filter, plus the fuel metering unit was knackered, so I've fitted a 2nd hand unit.  The car goes really well and as this is my first GTI (16V), I'm not sure of what to expect in terms of fuel consumption.

Any help, guidence or advise is welcome as usual  :wink:
Thanks
G

Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Horney on 15 June 2009, 13:13
The MPG reading works off a vacuum feed from the inlet manifold. A little pipe is conected to the back of the clocks. It's likely this is either completley missing, diconnected or has a crack in it causing the reading to be way out.

Nick
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Procomp on 15 June 2009, 13:29
Nick
Cheers for the info......will look to see if first off I have the vacuum pipe and if so, that it's connected and in good working order.

G
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Ben Lessani on 15 June 2009, 21:05
My MFA is just stupid only thing that works is the trip counter, MPG never gets above 12 - even though I'm hitting about 35-45 mpg most of the time.
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: JC on 15 June 2009, 21:08
only way u will get a true MPG figure,

fill up - reset trip - drive - fill up work out figures.

but as your speedo and trip will be out then it wont be that good a figure anyway  :grin:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: theclash on 15 June 2009, 21:14
i get about 140 mile to 20 quid thats town driving but petrols pound a litre so i dont know if thats good or bad.
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: JC on 15 June 2009, 21:17
oooooooooo maths this time of night


20 quid = 20 litres

20 /  4.454 = 4.49  gallons

140 / 4.49 = 31.2 mpg

I think  :grin: :laugh:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: theclash on 15 June 2009, 21:26
oooooooooo maths this time of night


20 quid = 20 litres

20 /  4.454 = 4.49  gallons

140 / 4.49 = 31.2 mpg

I think  :grin: :laugh:

flippin eck.... i wish i listend in school    :laugh:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: JC on 15 June 2009, 21:30
didnt say it was rite  :grin:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Jay on 16 June 2009, 23:19
Flippen heck, doing maths at this time of night  :shocked:

http://www.torquecars.com/tools/uk-mpg-calculator.php

Says 31.82 so not a bad calculation Chuff  :wink:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Horney on 16 June 2009, 23:23
Yikes! Worked out mine today and got 22mpg out of the Rado :cry:

nick
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: JC on 16 June 2009, 23:50
 :grin: :grin: :grin: :grin: :grin: :grin:

i gave up doing mine last time fuel hit £1 a litre  :laugh:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Horney on 16 June 2009, 23:57
Sad times when your track car is more economical than your daily (Golf is returning high 30's if driven nicely).

Nick
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: JC on 17 June 2009, 00:02
For sale - one rado, time for a dieseal nick for work  :lipsrsealed:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: mr self destruct on 17 June 2009, 07:11
I have the opposite problem. My MFA regularly tells me I'm doing 45-50mpg and when I work it our the proper way, I'm only getting 25!  :cry:
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: VeeDubGTI16v on 17 June 2009, 07:58
Sad times when your track car is more economical than your daily (Golf is returning high 30's if driven nicely).

Nick

 :grin: same here

best whack some twin webbers on there to restore the balance
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: Horney on 17 June 2009, 08:11
If it wasn't a damn cat car I'd stick it on bike carbs but ITB's and custom mapping is out of my budget. I need to get it on a rolling road really and see if it's running right. I suspect that the Lambda is playing up and it's over fuelling a bit. It's been running much better since you set my timing though!

Nick
Title: Re: Dodgy MFA or Poor Fuel Consumption??
Post by: VeeDubGTI16v on 17 June 2009, 11:54
no i mean make the golf juicier!

ill have a look in that bosch book to see what you can fiddle with on your rado, you should be seeing more than 22mpg