hey all,
id appreciate it if you my fellow a4 owners can help me diagnose this problem im having with my 1.8TQM

i had my baby chipped with a garrett 1bar chip on friday. on the drive back from philly to nyc, i floored it about 10-15 times, felt the boost, had the smile, etc. boost would top off at around 18 psi, then would gradually come down to about 12. nice linear power curve once the boost was turned on.
i was more than satisfied with my chip until saturday evening. with the extra boost, i became boost happy.. accelerating everywhere and anywhere i could. then on one of my acceleration binges, i was in 3rd doing about 35mph, and floored it. my boost gauge immediately hit 18psi, then jerked down to about 12, back up to 15, back down to 10, back to 15, back to 10.. basically up and down in a pattern like manner.
right afterwards, my gas light came on, so i thought that it may have been cuz i was low on gas and my "smart" car decided that it was a bad idea to floor it with no gas.. so i fed my baby a full tank of sunoco ultra 94. right out of the gas station i floored it and the boost fluctuation continued.
since saturday, ive tried flooring her about 8 other times and noticed the same thing.

is this the knock sensors retarding my timing?
i threw in a can of NOS octane booster last night and it still does the same thing.
is it my turbo?
and in the worst case senerio, did i burn a cylinder?

i dont think its the turbo cuz i dont see any smoke or oil coming from the general area.. my exhaust isnt smoking..

i really hope its not my motor.. has anyone else ever noticed that when something like this happens you notice that your engine makes a weird noise that you havent noticed before??

i really do think its the chip. im going to call todd at AWE when they open and see if i can get my hands on a less-pinging programmed chip.

what do you think? has this happened to you? tell me what it is.. im getting really worried..

oh, i have a blow off valve that bleeds to atmosphere.. does that have anything to do with it? my car was working fine with the bov before the chip.


help!

If not it might make a difference.

As for mechanical causes, all are doubtful but possible. Most mechanical things(like the wastegate rod) either break completely or slowly degrage. They don't fluctuate like you're describing.

What's the point of the blow-off valve in a car where the computer controls the turbo?

nt

any hoses, and sark plugs to make sure they arent loose. i have a feeling you have a slight vacuum leak and thats whats causing the stutter.

Ned

todd at awe knew about the bov..

i just got in from removing the bov and installing my oem dump valve, reset the ecu, checked vacuum lines, hoses, ic piping, etc.

took her for out for a spin.. still doing the same. this time i was inside a tunnel.. i floored it, and heard what was described to me as pinging.

still pinging after using sunoco ultra 94 and NOS octane booster.

todd at awe told me that garrett makes a "less pinging" chip for cars that were tempermental.

*sigh*

even tho with these problems, id still recommend the garrett chip over anything else out there in the market.

Why would you still recommend the chip? Pinging is bad for the engine. A less pinging chip would also have less performance.

So where exactly is the attraction?

One of the reasons that aftermarket chips can increase engine performance is that they are tuned more agressively than stock. The manufacturer has to take into account every possible climate the car may be sold in, varying fuel quality, and the fact that some owners will insist on using the cheapest fuel they can find even though the engine requires higher octane. Tuners remove most of this margin for error, thereby raising engine performance. In addition, on the 1.8t they can crank up the turbo boost to further increase power output (this is where must of the improvement comes from). If a chipped car pings, the tuner simply needs to back off and get a little less agressive for that particular car. The more agressive tuning may work just fine for someone in a temperate climate using 94 octane, but ping like heck for someone living in a tropical or subtropical climate useing 91 octane. One of the big advantages to working with a tuner in your area is they know your conditions, and if there's a problem they can fix it immediately.

Yes, the "less pinging" chip will have less performance, BUT it will still have much more than stock.

Regards,
Rodney

'99 A4 1.8tqms

I noticed your thread about the Garrett chip. I run my '99.5 with Garrett 1 bar on either 93 Citgo or 94 Sunoco depending on where I am in Connecticut when I need a fill up.

I've run the chip in 100+ air temp with high humidity, on 93 and had NO pinging. Never tried it with anything less in stock or tuned form.

I think it might just be that each car is different and some can handle the tuning better
and others can't. Best bet is to talk to Garrett
and/or Todd. They'll fix you up!

-Jenner
'99.5 1.8T QMS Spoiler/Garrett

My APR chip had a slight bit of pinging when jumping on the throttle at 2k in 2nd gear. It also had ragged acceleration in 4th and 5th. The ragged acceleration would manifest itself when I umped on it at ~60mph in 5th. The car would take off but the acceleration felt like the computer was changing the timing at a high frequency.

APR changed the chip and it seems great now but they thought carbonization could be a contributing factor and I should have it decarbonized. I'm going to have it done at the 30K service(another 1500 to go).