Help! Fluttering boost issue. With the cruise on doing 65mph in 6th my boost gage starts
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Help! Fluttering boost issue. With the cruise on doing 65mph in 6th my boost gage starts
wavering between normal vacuum and an inch or two more. This is accompanies by a slight physical shudder in the car. I haven't vag'd it yet. Could a bad N75 cause a condition like this? What could cause the car to pull more vacuum for a split second?
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Interesting. I've had that problem for a while now. What programing?
<center><img src="http://images28.fotki.com/v1031/file0QPc/50ae7/7/751624/5476919/image001.gif"></center><p>
"Boost flutter" is just my stupid name for it.
This is light throttle from 3000-4000. It will bounce between 0-6psi(depending on how much gas I give it) @ light cruise. Once boost comes on strong, it goes away. I'm on ASP code and I don't remember it happening on GIAC X. If our problems are the same, it is not DV/N75/FPR/leak.
Things I've checked:
Pressure test to 20psi= all good
Replaced with known DVs= all good
FPR= all good
Replace N75 with new=no change
This is just a small sample of what it looks like via Zeitronix a while back. No AFR or tps when I did this. I'll re do it with all the data since I've got all the sensors hooked up now. Again, this is light throttle and not a WOT FATS run.
I still need to check the WG balance. Some have pointed to an imbalance that could cause a boost feedback loop that might cause the issue.
Annoying ain't it? Listening for any ideas.
"Boost flutter" is just my stupid name for it.
This is light throttle from 3000-4000. It will bounce between 0-6psi(depending on how much gas I give it) @ light cruise. Once boost comes on strong, it goes away. I'm on ASP code and I don't remember it happening on GIAC X. If our problems are the same, it is not DV/N75/FPR/leak.
Things I've checked:
Pressure test to 20psi= all good
Replaced with known DVs= all good
FPR= all good
Replace N75 with new=no change
This is just a small sample of what it looks like via Zeitronix a while back. No AFR or tps when I did this. I'll re do it with all the data since I've got all the sensors hooked up now. Again, this is light throttle and not a WOT FATS run.
I still need to check the WG balance. Some have pointed to an imbalance that could cause a boost feedback loop that might cause the issue.
Annoying ain't it? Listening for any ideas.
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