mawilso24

I have a 2001 A4 Camaro SS with American Racing Headers just installed with a set of Richmond 373 gears, a K and N cold air unit and a 160 degree thermostat. I gained some nice HP to the rear wheels. I went from a baseline (stock) 305 hp to 340 hp on the dyno. Great numbers in my opinion for the $. Anyhow, I am noticing some hesitation in acceleration when I mash the pedal to the floor while cruising at speeds between 35 and 60 mph. There seems to be a half second delay from the time I floor-it until the car puts me back into the seat. The car drives fine other than this issue. I called the guy who installed and tuned the car. He is saying it is because I need a bigger stall converter. Well, shouldn't my stock stall be locked up when driving at these speeds and it shouldn't matter? Is this a bad tune? Is this normal for an A4? Why would he say I need a bigger stall? I am not having any idling issues, my car responds great from a standstill, and there are no lights on my dash going-off. I hope to recieve some feedback from anyone this might have happened to. Thanks.

Darkman

iTrader: (2)

Is your cam stock? If not, what is it?

ULTIMATEORANGESS

iTrader: (4)

would you say its a hesitation or a dead spot? 35 is not the best for performance with a stock converter.

km346

iTrader: (4)

sounds like its transmission related IMO. Does it seem like it hesitates while downshifting? I know the 4l60 in my truck sometimes takes a second to downshift into 1st at certain speeds when i punch it. Almost like its unsure if it really wants to downshift or not lol.

mawilso24

The cam is stock

mawilso24

Not quite sure if hesitation or a dead spot. Not really sure what a dead spot is. But all I know is, I didn't notice it before the install of the headers and other equipment and tune.

Darkman

iTrader: (2)

In that case, I suspect the problem is in the tune rather than the stall.

omarrakeen

iTrader: (2)

did it instantly happen after the tune? or was it there before the tune? if it was before the tune id say wires\plugs, if after then its just the tune. good luck.

senicalj4579

iTrader: (41)

No codes? Im suprised no one has mentioned anything about o2s going bad. Before I got my stall I experienced weird stumbling and it was my o2s going bad. I also was having no idle issues.

joecar

Is your MAF descreened...?

mawilso24

I first noticed it after the tune. Maybe it is the tune?

mawilso24

I have the original screen on the MAF, and I just looked at it. All clear and no obstructions. Do you think having the screen on would cause hesitation?

mawilso24

When you say stumbling, are you referring to what I explained during 30 - 50 mph driving?

Darkman

iTrader: (2)

Descreening an MAF can introduce air stream turbulence, which in turn can cause throttle response issues.

If you oiled that K&N filter when you installed the K&N CAI you may have oil fouled the sensing wires in the MAF. (If you did not oil it, of course it is not the issue.) If so, you can clean with some CRC MAF cleaner which is supposed to be safe. (Cleaning the MAF sensing wires with the worng chemical can ruin them).

The problem could be a number of things including the tune.

(I just do not believe that adding headers to an otherwise stock motor necessitates a higher stall.)

joecar

I think you will need to install a wideband and capture a few logs.

mawilso24

Sorry, I dont know what this means?

mawilso24

Wouldn't the stock converter already be locked up at 40 or 50 mph? If that is the case, then like you mentioned, a stall shouldn't be needed to solve the problem. Also, I don't understand why the stock stall would cause the slight hesitation when I mash the pedal to the floor while driving 40 - 50 mph? Just doesnt make sense to me. IMO, I believe the PCM-for-less plug and play tune just wasn't enough for the tune to be completly thorough. Additional time probably wasn't spent to further analyze other parameters. Anyways, just my two cents.