FungusMungus05

iTrader: (1)

I've taken the car back to the shop 4 times already and can't seem to make the car stay where it should be...

Here is the problem, after cam/stall/tune the car doesn't want to stay on on cold or warm start ups. I took back to the shop and they have fixed the start up idle and runs good for about 1 week or so and then all of a sudden one morning it shuts off on start up. I have to give it a little bit off gas for it to start up.

Is there such thing as a tune going away? It never dies on me at lights, in reverse, etc... It's weird that they address the issue and the car runs fine for a week then it just seems like the tune goes away

You think you it might be the TPS sensor? Should I take it off and give it a clean? Any other suggestions?

It sux because the car runs great, makes good power, once I do manage to get her up and running she runs fine no problems whatsoever...

hellbents10

iTrader: (10)

I would do a log on the start ups then. See what is gone array at those times. A tune does not go away, something else is causing you trouble.

FungusMungus05

iTrader: (1)

I'll take it to the shop once again and see if they can figure out something.
It just seems so weird how for a week it starts up fine then next week it goes crazy.

Thanks,

soundengineer

iTrader: (16)

sounds more like they dont know what they are doing with idle tuning...
IF they do a proper cold start RAF..in gear and PArk Neutral for an a4...
then they you would have no problems with your startup or your idle....
they may have jacked the wrong tables to get what they feel is right...and they might have done your tune in the "normal dyno tuner" methods....which are typically not the right ways to do things...
you are more than welcome to send me a bin file or a hpt file if you can get somebody from your area to read your car(I am assuming you dont have the software cause you are going to a shop for a tune)

Bink

Actually tunes (bad ones) can and do go away - as the trims go out of range.

For example - if your Idle Short Term Correction (air) trims are set at a max. of 2.00 g/sec at 60*C and your engine requires 4.00 g/sec (say Short Term Corr. = 4.00 g/sec at 40*C) then it may stall at 60*C transition. The Short Term Adjustment swings to try and correct but can't add enough additional air fast enough. If the 60*C max. was set at 4.00 instead of 2.00 g/sec then it may have had a learned value closer to 4.00 that would allow it it reach the needed airflow faster.
Another scenario would be if the 60*C value IS 4.00 but the learned value at 60*C was 1.22 g/sec. Again there would be a huge gap between the needed air 4.00 and the learned value 1.22. If at the beginning of the new tune the learned value was closer to 4.00 then it may have learned downward as the week went on. Until it reached 1.22 g/sec and needed 4.00...stall.

Hope this helps some. Just using generic extreme values.

ToplessTexan

Joel, can I quibble a little about language here? I would not say that the tune goes away. Way too many people have the impression that something mysterious can happen and the tune they spent hard earned money on gets bit rot or something. I would say that the performance obtained by the (bad) tune wanders. That's the definition of a bad tune.

Bink

You are absolutely right - poor choice of words/verbage on my part. Sorry.
Thanks for making it clear.

Have a Great weekend!

joel