Need Some help w/ weird Knock
Need Some help w/ weird Knock I have a 00 Vette w/ A&A ATI kit.. pushing 5-6# of boost....
Right now I am getting this weird knock problem and I have been fighting it for a while.
In 4th gear I can mash it WOT all the way to 6k and get maybe 1* of knock around 57-58k, but when I am in 2nd or 3rd gear and do the same thing I will get 5-8* of knock same thing I will get knock from about 0.72 (g/cyl) @ 3800rpms all the way up to 6k WOT....
I changed my plugs and ran a can of sea-foam through the motor to clean all the carbon and crap out...
Also i already have the maxium amount timing set at 6* WOT....
Right now I am getting this weird knock problem and I have been fighting it for a while.
In 4th gear I can mash it WOT all the way to 6k and get maybe 1* of knock around 57-58k, but when I am in 2nd or 3rd gear and do the same thing I will get 5-8* of knock same thing I will get knock from about 0.72 (g/cyl) @ 3800rpms all the way up to 6k WOT....
I changed my plugs and ran a can of sea-foam through the motor to clean all the carbon and crap out...
Also i already have the maxium amount timing set at 6* WOT....
My guess is that you are running lean. I'm thinking the engine spools faster in 2nd and 3rd, therefore runs out of fuel quicker than in 4th. I would also be interested to see what the commanded AFR is.
Looking at the attached graph, looks like there's an issue with fuel. Couple of observations:
Also, as an aside. If the PE multiplier is 1.1992, that works out to a commanded AFR of 12.24 (14.68/1.1992). If you were seeing 10.x AFR, then something else is adding fuel.
I'll send you a PM with my email. If you want, send me your bin file and I'll take a look at it.
- Injector duty cycle is 85%
- Injector durations are 20 msec. This seems like an awful long duration to me
- Timing advance is only 2.5*
Also, as an aside. If the PE multiplier is 1.1992, that works out to a commanded AFR of 12.24 (14.68/1.1992). If you were seeing 10.x AFR, then something else is adding fuel.
I'll send you a PM with my email. If you want, send me your bin file and I'll take a look at it.
Last edited by muncie21; Mar 22, 2006 at 11:20 AM.
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From: So.Cal.
Originally Posted by muncie21
From my understanding (and I could be wrong here), KR is a result of:
1) Lean condition
2) Too much timing
3) False knock
From your graph, I would eliminate #2 from the equation.
1) Lean condition
2) Too much timing
3) False knock
From your graph, I would eliminate #2 from the equation.
5) Intake air too hot
6) Spark plugs too hot
7) Bad gas
8) Too much oil (thru PCV)
9) CR too high
What about #7 and #8...?
And lean condition can be caused by airflow calculation not being correct (MAF, VE table, MAF table).