AAN problem. Ignition timing. Knock sensors...?

[Knight Rider S4]

Only other thing that it could be is fault with ecu as you have checked all other avenues with no succes and you mention that it was not registering knock sensor not been connected its quite possible

[Biggy]

sound in exhaust will be unburnt fuel igniting maybe?....love Moscow by the way had a ball there last year was working in the Mariott Aurrora ...Shandra very nice club to go to!!

may be, but i see no smoke at all. and as we can see on the graph - ecu is lowering the injector duty....

i'm not really fond of clubbing, but yes, its a nice place....

[Biggy]

Only other thing that it could be is fault with ecu as you have checked all other avenues with no succes and you mention that it was not registering knock sensor not been connected its quite possible

i've changed ecu, put eeproms to another ecu, changed eeproms, tried another ecu with stock rs2 software, put another map sensor...

performance is changing, boost is changing, but the whole character of the engine and this "malfunction" remains the same..

[Biggy]

by the way, i tried disconnecting knock sensors on another S4... it also didnt show any fault codes..

[Knight Rider S4]

N75 valve ?.have you looked at that?

[Biggy]

N75 valve ?.have you looked at that?

N75... brand new. recently installed. why r u asking?

[Biggy]

N75 valve ?.have you looked at that?

by the way... i`m using stock aan toothed belt pulley, not rs2 one.. can it cause such problems?

[urquattro-island]

have

you tried checking the fuel pump, and pump relee, the sparkplugs, fuel filter. Can be some shi... in the tank..

My old s4 was like this, just before the fuelpump broke.. fuel line in front of fuel filter, is it ok, has a tendence to brake, this was a call back from audi back in the days.
check the fuse for the engine control unit also.

[Biggy]

you tried checking the fuel pump, and pump relee, the sparkplugs, fuel filter. Can be some shi... in the tank..

My old s4 was like this, just before the fuelpump broke.. fuel line in front of fuel filter, is it ok, has a tendence to brake, this was a call back from audi back in the days.
check the fuse for the engine control unit also.

fuel pump, pump relee, sparkplugs, fuel filter and fuel line are checked.

[Mike Wakefield]

http://www.s2forum.com/forum/attachment.php?attachmentid=13064&stc=1&d=1179171072

1. If this chart from a post above shows the injector ms dropping while rpm increases, then boost must be dropping, since the lambda doesn't change significantly. Does the wastegate have a torn diaphram? Is the charge pressure control actuating valve working properly
2. Have you changed the spark plugs?

[Biggy]

http://www.s2forum.com/forum/attachm...1&d=1179171072
1. If this chart from a post above shows the injector ms dropping while rpm increases, then boost must be dropping, since the lambda doesn't change significantly. Does the wastegate have a torn diaphram? Is the charge pressure control actuating valve working properly
2. Have you changed the spark plugs?

1) diaphragm is ok. N75 working properly. boost is dropping because of a small standart rs2 turbo.

2) yes, 3 times in one day.

[Mike Wakefield]

You said car is lowered. Are you running stock cats? If cats hit something in the road and break the ceramic in the cats, it can produce significant back pressure at high rpm and a strange sound in the exhaust. I would suggest putting a pressure gauge on the down pipe (maybe in place of the oxygen sensor) and rev it up once. I have seen 25 psi from a similar occurance. Good luck!
Mike

[Biggy]

You said car is lowered. Are you running stock cats? If cats hit something in the road and break the ceramic in the cats, it can produce significant back pressure at high rpm and a strange sound in the exhaust. I would suggest putting a pressure gauge on the down pipe (maybe in place of the oxygen sensor) and rev it up once. I have seen 25 psi from a similar occurance. Good luck!
Mike

3 inches in diameter. from turbo to the tailpipe. no cats. only rear muffler.

[urquattro-island]

have you

checked the turbo impeller for movement. could it be??

[Biggy]

checked the turbo impeller for movement. could it be??

no. threre is no problem with boost or turbo....