[s-cars] Knock Sensors?

[Bill Clancy]

oops... hit send by mistake.   I meant to include the source of that info.

http://members.aol.com/c1j1miller/ecu.html#Ignition%20Coil,%20Output%20Stage,%20Distributor


----- Original Message ----- 
From: "Bill Clancy" <clancybill at yahoo.com>
To: "Bill Clancy" <clancybill at yahoo.com>; <s-car-list at audifans.com>
Sent: Tuesday, May 24, 2005 5:46 PM
Subject: Re: [s-cars] Knock Sensors?


>I just stumbled on this.   It confirms that the engine is detecting a 
>knock.
>
>
> If knocking is detected for an extended period of time, the ignition 
> timing is retarded and the boost pressure is reduced. Ignition timing is 
> retarded in 3° increments.
>
> Should knock continue after timing retard, the ECU will enrich the fuel 
> mixture to reduce the combustion temperature; should knock continue, the 
> ECU will then reduce boost pressure to a predetermined level.  When knock 
> has been eliminated, the ignition timing is returned to its normal value 
> in 1.3° increments and boost pressure is returned to its normal value.
>
> ----- Original Message ----- 
> From: "Bill Clancy" <clancybill at yahoo.com>
> To: <s-car-list at audifans.com>
> Sent: Tuesday, May 24, 2005 4:59 PM
> Subject: [s-cars] Knock Sensors?
>
>
>
> Does anyone know if there is a way to check the knock sensors?   Or is 
> there a way to disable them temporarily to see how the engine runs?
>
> I continue to get inconsistent performance.   It runs better with all the 
> turbo leaks fixed and with new spark plugs... but I still feel the engine 
> sort of sputter and back off a bit at WOT.    It's been suggested that the 
> ECU senses a knock and backs off the timing.    I did do some road testing 
> with the VAG-COM software on my laptop and I think I can correlate the 
> power loss to the timing -- at WOT at @3500RPM the timing moved up to 12.8 
> BTDC, then it moved to 9.8 (I think that's the power loss I feel), and 
> then back to 11 or 12.    On a good run the timing seems to stay at 12.8. 
> On a better run, sometimes I record 13 or higher.
>
> I have another fuel/timing chip for 91 octane that Mr. Myers provided, but 
> I am not yet convinced that the problem is knocking 91 octane fuel.    Or 
> maybe it is.   Could it really be that simple?
>
>
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