Audi 80 troubles

[shaun5]

I know this is an S2 site but im having trouble getting my 80 2.0e saloon to run rite, i use it as my daily drive to save putting the miles on the S2 and it's supposed to be more economical than the S2 but im only getting 15 mpg . the car runs and drives ok but when you are accelerating it misses every now and again. Ive tried a different maf, spark plug leads, lamba sensor, the timing is correct but it still happens. I haven't got around to fitting new plugs yet. Has anybody got any ideas what could be wrong with it, any advice would be greatly welcomed if i cant sort it the S2 will have to get wet

[Gompa]

have you checked all hoses for perishment? can upset them terribly if they have small air leak

[jameswkr]

Clogged air filter ? Damaged cat ?

[shaun5]

I forgot to say its got a new cat (or it looks new and ive had the exhaust down and its not blocked up/broken up) the air filter is new. Ive cleaned all the breather pipes with brake cleaner. I'll check the intake hoses but dont think its that time will tell. Im really scratching my head now, looks like i'll have to send it to the professionals

[jameswkr]

How are you computing MPG ?

[shaun5]

when the fuel gauge is on the red i put in £20 of fuel and record how many miles it does until it goes in the red again, then work it out.

[Trist28]

Only way to get accurate MPG is fill at the same pump, filling to brim, to say two clicks off with the nozzle. Reset miles, do some mileage then when you refil note litres used and miles on the clock. Litres divided by 4.55 gives you gallons. No of miles divided by no of gallons, there is your answer. If your only doing short journeys (10 mins driving or so) the car never gets upto working temp, so will never attain good MPG, only long journeys will give decent figures.

[Trist28]

Oh.... And change your plugs, my 2.0 16V quattro was doing the same thing on acceleration, plugs were slightly loose and very old, changed them made a world of difference!! The 2.0 16V and my S2 do around the same MPG on short runs....

[macspring]

What about

your lambda probe? Not sure how you test it, as a new one can be dear enough if your not sure it is in fact acting up?

Let us all know if and when you find the cause?

Kind regards.

[shaun5]

Well i had to get my car looked at There turned out to be two things wrong with it, a water temperature sensor (the blue one) was faulty and it had an after market lambda sensor which was knackered, it went to a VW specialist and they recomended to only fit a genuine one, luckily i had a spare one (genuine) from a car i broke. Stuck that one in and it now runs loads better. Hopefully i'll get better MPG now.