patrarch
15+ Year Contributor
- 46
- 1
- May 10, 2006
-
Layton,
Utah
The problem from my previous post about the weird stutter backfire thing now occurs regularly between 2 and 3 rpms, and thats it. I tried a new maf-t, and it did nothing. I have now realized it has nothng to do with the maf or tuning. I found that whenever I press the clutch in just a tiny bit (pretty much just rest my foot on the pedal) through 2 to 3 rpms in each gear, the symptoms completely disappear. What the hell? Its not pressing the pedal enough to disengage the clutch at all, but for some reason it fixes my problem. Any idea whats going on or why or how to fix it? I have clutch cut disabled on dsmlink and i haven't installed the wire yet, but tomorrow i am going to be installing the wire and turning on clutch cut to see if that helps because it acts kindof how it did when i first got dsmlink and accidently enabled it without the wire. Any other ideas of what could be going on? I can't imagine anything that could be wrong with the clutch/flywheel assembly...Maybe bad master cylinder? I am going to try and adjust it inwards a little bit and see what happens. Any other ideas?
Tonight I tried a new maf, maft- no change. Fixed clutch cut wire and dsmlink settings, no change. Reset ECU and tuned nothing but the bare minimum fuel settings- no change. Changed tranny fluid- no change. I've pretty much narrowed it down to a clutch/flywheel problem of some kind. Heres a more detailed description of whats going on that explains why I think this:
It only backfires under boost. What I think is really happening is something with the clutch/flywheel is causing a sudden drop in RPMs which in turn, when under boost, causes a backfire (Not the other way around). Maybe loose flywheel bolts, burnt surface, warped pressure plate? This would explain why pressing the clutch a little bit makes the symptoms disappear-- relieving some of the pressure on the problem. When I log the occurence, like the log I am looking at right now-- I am going along gaining RPMs, at 3316 the next frame suddenly drops to 1506 RPMs, which is accompanied by a sudden loss of air and fuel. When this sudden RPM drop occurs under boost, it causes the backfiring symptom.
What I am asking is, do you think i'm right? Would anything like a warped pressure plate or messed up flywheel cause a sudden drop in RPMs? Any other ideas? I REALLY don't want to pull my tranny, especially if I don't have to.
Tonight I tried a new maf, maft- no change. Fixed clutch cut wire and dsmlink settings, no change. Reset ECU and tuned nothing but the bare minimum fuel settings- no change. Changed tranny fluid- no change. I've pretty much narrowed it down to a clutch/flywheel problem of some kind. Heres a more detailed description of whats going on that explains why I think this:
It only backfires under boost. What I think is really happening is something with the clutch/flywheel is causing a sudden drop in RPMs which in turn, when under boost, causes a backfire (Not the other way around). Maybe loose flywheel bolts, burnt surface, warped pressure plate? This would explain why pressing the clutch a little bit makes the symptoms disappear-- relieving some of the pressure on the problem. When I log the occurence, like the log I am looking at right now-- I am going along gaining RPMs, at 3316 the next frame suddenly drops to 1506 RPMs, which is accompanied by a sudden loss of air and fuel. When this sudden RPM drop occurs under boost, it causes the backfiring symptom.
What I am asking is, do you think i'm right? Would anything like a warped pressure plate or messed up flywheel cause a sudden drop in RPMs? Any other ideas? I REALLY don't want to pull my tranny, especially if I don't have to.
