Knock issues and looking for insight. Bring it on your logging gurus!

**MADMarc** · 01-22-2011, 01:22 AM

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I am at about 7k on some NGK coppers. Just swapped out my coil packs because the car has 170k, I never replaced them during the motor swap and couldn't find any receipts from the previous owner stating that it was ever done. Also, before I was having some nasty stuttering around 11 psi at higher RPMs under a load so figured why the hell not replace the packs.

I understand that the plugs are nearing their swap out time and I also know of one small boost leak (damn clutch booster line is hard as a rock) but my o2 voltages don't look drastic to me. What do you guys think? I am still terribly new at this manipulating my logs thing.

**Roybatty** · 01-22-2011, 07:55 AM

My knocking was fuel related; went with a walbro and always use 91 or higher.

**MADMarc** · 01-22-2011, 07:07 PM

But My thing is that if it were fuel related wouldn't it show on the trim? Could it still be a spark issue? I did feel slight studdering but not as bad as it used to be before swapping the coils.

**MADMarc** · 01-22-2011, 10:33 PM

Thanks for the input, Steve. I had problems when I gapped them to 32 so I bumped it to 38 (when the plugs were new) and the car ran fantastic until the recent issue. When I get back home I will check the sensors to make sure they fluctuate like they should.

**OhioSpyderman** · 01-23-2011, 11:57 AM

I could be WAY off here, but shouldn't your Air Volume be something other than 0?

Is that not the frequency reading from the MAF?

It's been a while since I've done any logging, so forgive me if my head is up my A$$

Bob.

**RealMcCoy** · 01-23-2011, 01:08 PM

Originally Posted by MADMarc

But My thing is that if it were fuel related wouldn't it show on the trim? Could it still be a spark issue? I did feel slight studdering but not as bad as it used to be before swapping the coils.

No.. Your issue is at WOT, the ECU is ignoring the O2 sensors and trim at that point. Providing your O2 sensors are working properly, and that the 0.9 I'm seeing on both sensors is truly 0.90, that's too lean.

But if you still have a misfire going on, you can't trust your O2 sensors anyway...

Originally Posted by OhioSpyderman

I could be WAY off here, but shouldn't your Air Volume be something other than 0?

Is that not the frequency reading from the MAF?

It's been a while since I've done any logging, so forgive me if my head is up my A$$

Bob.

Correct... But I expect it's a logger or database translation error. It does appear to be correctly calculating load, which requires the airflow signal.

**MADMarc** · 01-23-2011, 02:58 PM

Taking that into consideration and if it IS actually a fuel issue, then since both the front and rear banks are reading similar voltages (also considering that they are working correctly) how would I go about taking care of things? I have a denso 1020 as well as an AFPR but wasn't planning to toss them in until I got turbos. I don't expect it to harm anything if I do so and it would eliminate a possible fuel pump issue allowing me to log further to either eliminate that from my list or mitigate the knock entirely. Now, if it isn't the fuel pump, how can I go about testing the injectors? The filter was replaced when I did the swap so it has about 25k on it.

**RealMcCoy** · 01-23-2011, 03:01 PM

Is the car all stock at the moment?

**MADMarc** · 01-23-2011, 03:29 PM

For the most part. There are some simple goodies like the y-pipe, exhaust, profec spec II EBC, FIPK, fmic, fuel loop yadda yadda but nothing serious like fuel management or upgraded turbos.