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Author Topic: 13 yes13 MPG  (Read 1632 times)

Offline messenjah

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13 yes13 MPG
« on: 17 January 2011, 13:19 »
hi guys  some issues with my gti im getting 13 mpgfrom a standard 8vdigi


today im gonna swap the afm  because adjusting themixture screw does NOTHING   

recentlychanged the blue temp sensor for a genuine vag one gonna check the timing and put some injector cleaner through it


what else
should i look at ?
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Offline rob.043

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Re: 13 yes13 MPG
« Reply #1 on: 17 January 2011, 13:58 »
is there a screwdriver through the fuel tank!? Would be worth a good nose around for leaks...
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Offline SoundillusioN

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Re: 13 yes13 MPG
« Reply #2 on: 17 January 2011, 14:02 »
where are you getting these figures from?  If its the MFA I wouldn't trust it... work it out properly.. hows it running?
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Offline tony_ack

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Re: 13 yes13 MPG
« Reply #3 on: 17 January 2011, 14:46 »
Are you sure the screw is actually in? i.e. has the thread caught properly or is it just loose over the hole?

Also test the AFM by testing the resistance through it before you condemn it. I can't remember the exact reading range it needs to be, but it will tell you in Haynes. Think it's in the mid 20's somewhere..

Digis are fickle and need everything working and setting correctly and accurately to work properly (e.g. CO at 1.5-1.8, Timing 6deg BTDC @ 2-2.5k rpm).
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1992 VW Golf MK2 GTI
1995 VW Corrado VR6

Offline messenjah

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Re: 13 yes13 MPG
« Reply #4 on: 17 January 2011, 15:14 »
there are no leaks  yes the reading is coming from the mfa but i used £30 of petrol on a 100 mile trip last night which puts it at about 15 mpg roughly ...


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Offline clipperjay

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Re: 13 yes13 MPG
« Reply #5 on: 17 January 2011, 16:28 »
Thats an 8V @ 15MPG something is big time wrong!
I think its time to let a pro check your timming on it  :lipsrsealed:
If you have a sensor go down on your digi it will eat up 25% more fuel as the mapps are generic so possibly you will need to start testing or swapping out parts all electrical related to see if it helps?
Does it idle or drive rough? Smell any fuel from the vents?
The last time I saw figures like that was when the ECU was playing silly buggers  :undecided:
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Offline messenjah

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Re: 13 yes13 MPG
« Reply #6 on: 17 January 2011, 16:45 »
idle is a little lumpy  and there is a intermittant miss fire on light throttle
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Offline jezza16v

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Re: 13 yes13 MPG
« Reply #7 on: 17 January 2011, 17:11 »
Is the engine running at the right temp? The needle should be in the middle of the gauge, if the engine temp is low the blue sender will tell the ecu to keep the mixture enriched. If your temp is low then change the stat for a genuine one. Short journeys will also kill mpg.
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Offline messenjah

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Re: 13 yes13 MPG
« Reply #8 on: 17 January 2011, 17:25 »
temp only ever reads  1/4 of the gauge  so i guess that could be part of the problem ill change the stat 

im having trouble finding an afm and dont have a multimeter to check the resistance
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Offline richard s

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Re: 13 yes13 MPG
« Reply #9 on: 17 January 2011, 20:42 »
i had mpg figures like that on my mfa when i had the cam sprocket on the wrong way round on my 8v
the cam belt sitting a few mm over the front edge of the sprocket was the main giveaway that something was wrong
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