A3 'flat spot'

[catton63]

I have a 1.8T (57 plate) A3 which seems to be suffering from a flat spot when pullling away from a standing start. As I accelerate in first gear the revs drop momentarily and pick up again, very annoying and potentially dangerous.

My local dealer has test deiven the car and also checked the diagnostics, in their opinion all is normal with no faults recorded. They suggested that it may be my driving style but I have never experienced this with any other car I have driven.

Has anyone had a similar experience?

[Space Cadet]

Are you using decent Super-Unleaded petrol?

The 1.8T loves 99ron Shell V-power (or the like), if you haven’t done yet would be worth filling her up on this.

Have you thought about having your car re-mapped, would give a decent power increase and if there are any flat spots in the mapping these would be ironed out.

(….and no the garage would never be able to tell at service time.)

[catton63]

Thanks Space Cadet

I've only ever fuelled the car on 95 ron unleaded so will try 'super' as soon as I empty the tank.

With regard to re-mapping, I don't know much about this, can you direct me to any good sights?

Thanks again

[Space Cadet]

95 will be strangling your engine. 95 “un-leaded” was developed to appease the Green Party, but unfortunately engines love Octane and therefore perform better on higher rated petrol’s (99 is the equivalent of old 4-Star).

This is multiplied for turbo-charged cars.

So literally run your car down to fumes and stick ¼ of a tank of V-Power in to flush the rest of the unleaded out. Once this is all used up then fill up properly with V-Power.

You will notice the difference already after a few miles of driving once the unleaded has been flushed out. But after you have used up the ¼ tank and filled up again re-set your ECU by disconnecting the battery for 10 minutes.

Do this when the engine is cold, i.e. in the morning (obviously you’ll have to re-set your clock etc), rather than the ECU adapting to the new petrol over say 100miles of driving, because you have disconnected the battery it will sense it instantly when re-connected and adjust accordingly.

This also will re-set your throttle, so once the engine is warm go for a proper drive and give it some welly.

This will hopefully both have solved your flat-spot.

The above is worth doing anyway, but if you are still interested in a re-map take a look at http://amdtechnik.com/ (http://amdtechnik.com/)

Have used these guys literally dozens of times and spent too much money there, they might be a drive from you but would be more than worth it.

[catton63]

Thanks again

Sounds like this might just be the answer to my problem and I will certainly try it when the tank gets down. The only reason I am on 95 ron is because it states this on the inside of the filler flap.

I will let you know how I get on, you have given me a much better feeling about this than my local Audi dealer (not the one I purchased the car from by the way).

Cheers.

[RSTuning]

I'd advise a diagnostic run on the dyno and certainly NOT a remap if you feel you have a fault.

The car must be in good mechanical order before any software upgrade :)

It could be a maf fault or anything as simple as a throttle adaption.

Paul

[Space Cadet]

No problem, hope you get your car sorted.

Cars, whatever their engine, love to run on higher octane petrol.

My wife had a little Ka a few years ago and I/we could tell the difference putting Optimax (at the time) in it. Not that it turned it into sports car or anything, just that it was a lot smoother and a bit stronger. We always use it now in her Mini.

Now amplify this for your 1.8T and the difference will be a lot more dramatic.

I only use V-Power in my 3.2Q and it runs a lot smoother and stronger with it in.

And yes, a fault reading would be/was sensible, but as you’ve already said the garage has tried this.

Hopefully the petrol and ECU re-set will sort things out, if not (and I would advise a re-map anyway for the extra 40-50bhp) a re-map will iron out any flat-spots.

If you go somewhere like AMD they will check the car and the ECU out before they do anything. They should have their rolling road installed by now (they have changed locations) so you could have a pre-remap power run done to see what its pumping out before you have any work done.

[RSTuning]

It's always sensible for logs to be made on most vehicles before tuning. Recently we are seeing more and more fith faulty components.

Paul

[porterclough]

I have a 1.8T (57 plate) A3 which seems to be suffering from a flat spot when pullling away from a standing start. As I accelerate in first gear the revs drop momentarily and pick up again, very annoying and potentially dangerous.

...

Has anyone had a similar experience?





I've got an 05 plate 2.0 FSI and I've noticed a similar thing - if you lift off in 1st gear too soon before depressing the clutch to change up to 2nd the car slows down on the engine. I assume this is because if you rev it to 3000rpm in 1st then as soon as you lift off the engine will slow to 1500 or so very quickly.

It's much more noticable in this car than any other I've had but doesn't happen if I change up to 2nd sooner or don't lift off too sharply as I press the clutch pedal.

[catton63]

I'd advise a diagnostic run on the dyno and certainly NOT a remap if you feel you have a fault.

The car must be in good mechanical order before any software upgrade :)

It could be a maf fault or anything as simple as a throttle adaption.


Could you explain what a throttle adapyion is please.

Cheers