Pre-detonation (pinging or pinking) under those circumstances suggests lean conditions and/or a timing issue. You say you have perfect fuel pressure but when/how are you measuring it? With a 4 Bar FPR, you should have 4 Bar (58 psi) plus boost pressure at ALL times, e.g. at 22 psi (1.52 Bar) boost, the fuel rail needs to have 5.52 Bar (80 psig). Otherwise, the injectors will be supplying less fuel than the ECU expects them to do and pinging will occur until the ECU gets the feed back from the G61 and G66 knock sensors.
If your fuel pump is good and the fuel lines are somehow kinked, you might have a FPR problem. Click on the FPR label in the upper middle of this diagram (all the other labels are live links as well):
URS6 Way Too weak!!!
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Replaced the ECU with the cars original yesterday and went for a run. Can is now totally stamdard with a tank of super plus! Fuel pump wiring has now had the mod, had 13.9 volts at the pump and correct fuel pressure everytime. The temp reading according to vag-com is now between 94 and 97 when hot now. Air temp is also correct.It is more likely that there is an annoying wiring problem than an issue with the G4 crank position pin. That said, to give you piece of mind (maybe), you might want to remove the starter and rotate the engine (on a hoist, trans in 4th and move the front wheel) to inspect the condition of the G4 crank position pin.
More G4 crank position pin position, or lack or therein, here:
The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums

However coming off an island today next to an armco reservation, just as the car came on boost so to speak (around 3k) I could actually hear the thing pinking like a bitch just before it hung back untill around 4k (which its doing everytime its warm now)
Just went to data log and the thing pulled perfectly though
Any ideas what could make it pink with correct fuel pressure etc? My gut feeling is that something is causing week running but am clueless now as to what!!Leave a comment:
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It is more likely that there is an annoying wiring problem than an issue with the G4 crank position pin. That said, to give you piece of mind (maybe), you might want to remove the starter and rotate the engine (on a hoist, trans in 4th and move the front wheel) to inspect the condition of the G4 crank position pin.The two sensors are new and pulled them today and are still clean, i will check the wiring to them tomorrow as today i just ran out of my own time again! The horrible thought of it being something on the flywheel its self has crossed my mind too!!! Is this possible? Its as if the signal from this sensor is incorrect (too advanced)
More G4 crank position pin position, or lack or therein, here:
The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums
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The two sensors are new and pulled them today and are still clean, i will check the wiring to them tomorrow as today i just ran out of my own time again! The horrible thought of it being something on the flywheel its self has crossed my mind too!!! Is this possible?The G4 crank position sensor is one of the three sensors needed to start the AAN (and ABY and ADU) along with the G40 cam position sensor and G28 engine speed sensor. Once started, the G4 can fail (or be unplugged) and the ECU will continue to figure things out based on calculations it was making when the engine first started. On that basis, you might have an actual G4 sensor issue, e.g. tip clogged with debris or a wiring issue. Worth a check by pulling and inspecting the G4 and G28 twins. More info here:
http://forums.quattroworld.com/s4s6/msgs/20986.phtml
Its as if the signal from this sensor is incorrect (too advanced)Last edited by HMS-S6; 14 May 2012, 17:47.Leave a comment:
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The G4 crank position sensor is one of the three sensors needed to start the AAN (and ABY and ADU) along with the G40 cam position sensor and G28 engine speed sensor. Once started, the G4 can fail (or be unplugged) and the ECU will continue to figure things out based on calculations it was making when the engine first started. On that basis, you might have an actual G4 sensor issue, e.g. tip clogged with debris or a wiring issue. Worth a check by pulling and inspecting the G4 and G28 twins. More info here:
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Well! Looks like i cures a newer fault than the long standing intermittent surging!!! Took it for a run today and t was Crap! But, just as it used to be, if i start it, unplug the crank position sensor it pulls way way better!!! Any ideas? Does this knock out the knock control???Leave a comment:
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Glad it’s fixed.
You’ll enjoy it once you are free to drive it whenever you want.
Good to know the cause.
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This problem would be visible in VAG-COM though...
You know, if you run proper diagnostics with measuring blocks
Glad it's fixed.Leave a comment:
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Well, after 5 long years, its fixed!!! Pulls like a train
one one hand i'm pleased that its all good now but in one respect i wish it hadn't cost me over 3k to get here
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