MPG on MFA (seem's good) Miles to a Tank not good

[lingl9z]

Ok so basically, I have a Mk2 GTI 16v which at the minute is idling at 1200 (and I think still running slightly rich even though I've had the car retuned at a vw specialist)

I don't know if that would contribute to a poor miles per tank as I've been getting 30ish Mpg on the MFA (basically driving under 3k rev's) and I have got basically no miles outta the tank I'm sure it's sitting at 88 but I can't rememeber If I reset with a full tank, although I know it's not getting the miles it should be.... Any idea's ?

Thanks, Rich.

[raferackstraw]

can u turn down idle with screw on throttle body? did you get the isv sorted, also check your injector seals have not perished, also replace all vacuum lines, change/check sensors on side of head, check air intake boot for cracks, clean out engine breather hoses, give the metering head and throttle body a good clean with carb cleaner.
if you got the isv sorted and cant turn down idle with the screw there must be an air leak some where. the vac hoses may look ok but can be perished.
my high idle was caused by a dirty isv, and the lumpy idle i had was the injector seal on no1 cylinder
mine is usually 20-30mpg around town and 35+ on a steady run at 70-80mph

[lingl9z]

Thanks buddy, that gives me a nice long list of bits to check out, I'll try and search most of the things you've said to see how to do them if that makes sence. I've not yet done the ISV will hopefully be heading over to clipperjay's to try a known working isv on sunday! with any luck it'll sort the idle so it can be controlled via the screw, if not I'll look at the other bits! - I did have it in @ a vw specialist who claimed there was no airleak's etc but I guess they could be wrong!

[cняis]

i get around 250 miles on a tank in my vr6 which equates to approx 25mpg. you should be getting much better than that!

[Charge]

The something is seriously wrong with mine >.< lol I only just hit 200 motorway driving.

[lingl9z]

Strange, I mean the gauge could be faulty and I've never really taken it in to the red fully, don't believe in that! hmm I think I may fill a petrol can and keep it in the car drive it and see how many miles I can get!

[raferackstraw]

do not allow it to run dry mate you may open the injection system up to all sorts of trouble if any crap in the tank gets into system 

[lingl9z]

I tend not to ever go below half a tank to be honest with you! But when testing mpg etc I guess it's the only way, how far does the car run in to the red? I panic if I get to the top of it! Cheers buddy

[raferackstraw]

mine goes into red to just before first white marker on fuel gauge and its still going but there is no way i would run dry, if you get crap and rust in the injection system it will be farked big time and you will have much bigger problems than now.
 i think they are 9.5 gallon tanks  , so fill up to brim and note odo reading/ reset trip run around til your bang on half a tank and work out mpg, fill up again and see if you put the same as last time, may take  a few goes but better than running dry

[cняis]

mine goes into red to just before first white marker on fuel gauge and its still going but there is no way i would run dry, if you get crap and rust in the injection system it will be farked big time and you will have much bigger problems than now.
 i think they are 9.5 gallon tanks  , so fill up to brim and note odo reading/ reset trip run around til your bang on half a tank and work out mpg, fill up again and see if you put the same as last time, may take  a few goes but better than running dry

55 litres = approx 12.5 gallons