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Knock signal affected by RFI??


James1436215376
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Just wondering, while monitoring the ignition I notice that the ecu always puts the ignition back to static timing (9degrees) mainly in the 2nd row from 750rpm to 2250rpm, even just a few minutes down the road from getting underway and even to a ignition cell with 24degrees? I havent pushed the engine to see if Im getting knock events under high load I cant see a point for doing so. So Im wondering if RFI can influence the signal or if the engine is striking something in the engine bay as its quite tight in there with a DOHC 5litre V8, BTW the fuelling/ignition in those zones has not changed since it was initially tuned just over a year ago. The HT leads are standard Beru Mercedes parts with suppresors in the plug ends, spark plugs are NGK BCP6ES (youre not supposed to use resistor plugs with these wires), I have changed the coils to HEC715's but the originals were low ohm as well but maybe these are a cause? The engine is standard N/A with 10:1 comp and I always run 98octane gas. At the end of a 20min deive I would have over 200 knock events recorded whilst only have driven the car normally as in not exceeding 3000rpm or putting it through high load. Can anyone help, the car is booked in at the dyno on the 29th but opinions would be appreciated.

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You may have your knock base RPM and sensitivity settings too low and general engine noise is causing timing to be removed.  It is possible that interference is the problem.  Take the knock sensors out and just ground them to the block with a very short wire to see if the problem goes away.  At least that will tell you if it is interference or engine noise.  Engine noise is always present and increases with RPM...

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