GIAC chip temperature sensitive?
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GIAC chip temperature sensitive?
Can anyone w/ a GIAC chip chime in? I have the latest GIAC software for the non-DBW A4 1.8T and I've experienced boost surging this past winter. Now in the warm weather, w/o any changes other than the weather and non-oxygenated fuel, no more surging.
What's going on?
TM
What's going on?
TM
Audiworld Senior Member
Joined: Mar 2000
Posts: 483
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From: USA
Re: GIAC chip temperature sensitive?
It sounds like the diverter valve to me. Boost surging is a common symptom of a leaking diverter valve. AWE has the Bailey's which I just installed in one of my cars. My wife's car also has the surgy feeling.
If the pedal is depressed putting down a smooth throttle input the power delivery feels somewhat jerky (like off and on, but not pinging). Is that what you are experiencing?
If the pedal is depressed putting down a smooth throttle input the power delivery feels somewhat jerky (like off and on, but not pinging). Is that what you are experiencing?
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Please read inside (more)
Can you explain why the surging only occurred in cold weather and not in hot? If it were the bypass valve, why would it only happen in cold weather?
AWE's explanation was a bad bypass valve. If that were the case, I need to understand why the problem only exhibited itself in cold weather.
Everyone just jumps on the bandwagon and mentions bypass valve. I don't buy that explanation without some further explanation as to why the leak would cause surging and how it could be temperature sensitive. I'd also like to know why this is not exhibited on the I-5 Audis nor on Porsche turbos (at least the 951). The bypass valve plumbing is not significantly different and they all use the same valve (the same exact part).
Sorry if I come off as being harsh- I'm pissed that no one has a better explanation than a bad bypass valve and I have not heard anything to back up that diagnosis. I'm going to call Garrett Lim if I have to in order to get this issue resolved.
TM
AWE's explanation was a bad bypass valve. If that were the case, I need to understand why the problem only exhibited itself in cold weather.
Everyone just jumps on the bandwagon and mentions bypass valve. I don't buy that explanation without some further explanation as to why the leak would cause surging and how it could be temperature sensitive. I'd also like to know why this is not exhibited on the I-5 Audis nor on Porsche turbos (at least the 951). The bypass valve plumbing is not significantly different and they all use the same valve (the same exact part).
Sorry if I come off as being harsh- I'm pissed that no one has a better explanation than a bad bypass valve and I have not heard anything to back up that diagnosis. I'm going to call Garrett Lim if I have to in order to get this issue resolved.
TM
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From: USA
Re: Please read inside (more)
I'm not one to jump on the bandwagon replace the bypass valve, I've been one of the biggest anti-DV pre-replacement people myself. Why replace a perfectly functioning part was always my arguement. The DV was and mainly is a problem on transverse 1.8T engines, although there are some longitidunal motors that have it.
I'm also not technical enough to tell you why you were surging in cold weather and not hot. My wife's car exhibits the problem in cold and hot weather.
VW/Audi has recognized it as a problem. From what I understand there is a recall currently in place for some model cars.
What octane gas do you run? It very well could be the gas. The oxygenation (correct term?) procedure might lower the octane rating so many points and you might have inaudible pinging.
Don't throw out the window what AWE tells you either. Todd is one of the most honest guys out there, he will not sell you something that you don't need!
I'm also not technical enough to tell you why you were surging in cold weather and not hot. My wife's car exhibits the problem in cold and hot weather.
VW/Audi has recognized it as a problem. From what I understand there is a recall currently in place for some model cars.
What octane gas do you run? It very well could be the gas. The oxygenation (correct term?) procedure might lower the octane rating so many points and you might have inaudible pinging.
Don't throw out the window what AWE tells you either. Todd is one of the most honest guys out there, he will not sell you something that you don't need!
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You could have used VWtool
I know it doeesn't help you now. We used VWtool to identify that in hot weather with 900 lbs of people in the car going up a hill I was dropping 4 degrees of timing on my motor.
Without a log of what happened, I guess we could outline what could cause surging:
timing
boost pressure
bad fuel
mixture
Others?
The different oxygenated fules for winter use may have caused detonation which caused your timing to get pulled back, but w/o a chart I dunno.
Do you have a boost gauge?
Without a log of what happened, I guess we could outline what could cause surging:
timing
boost pressure
bad fuel
mixture
Others?
The different oxygenated fules for winter use may have caused detonation which caused your timing to get pulled back, but w/o a chart I dunno.
Do you have a boost gauge?
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Yes, I have a boost gauge (more)
That is why I posted fairly close figures as to where exactly I was experiencing the surging.
Now this occurred throughout the winter with several tanks of gas- we only use 93 octane premium and this occurred with gas bought from several different stations as well.
Unfortunately, I don't have a VWTool, so I can't tell you exactly what the ECU is doing.
Would the computer retard the timing, advance it, retard it, etc. in enough cycles to cause this?
TM
Now this occurred throughout the winter with several tanks of gas- we only use 93 octane premium and this occurred with gas bought from several different stations as well.
Unfortunately, I don't have a VWTool, so I can't tell you exactly what the ECU is doing.
Would the computer retard the timing, advance it, retard it, etc. in enough cycles to cause this?
TM