View Full Version : Knock Retard
NAH
May 19th, 2007, 12:58 AM
On every run I log, I get 4-5° of KR. I've tried reducing the timing according, but the KR just appears in a different place.
A typical occurance is shown on the picture linked below.
http://ph.uncle-dave.co.uk/upload/images/0092%20-1.jpg
Also, the injectors are running up to 150% even I have an up-rated fuel pump & 42lb injectors fitted. I am in the process of fitting a MAP Bost & Fuel Pressure Gauge.
Perhaps the knock sensors are just having a benny :mad:
joecar
May 19th, 2007, 04:07 AM
NAH,
That KR might be real...
It has a sawtooth shape and coincides with load (TP, MAP, g/s, g/cyl).
Your timing is already low at 10° or less and your AFR is sufficently rich at 10-11 in the region where knock is shown.
Sounds like it's inaudible.
It's hard to say...
You may have to try some octane boost to see if it makes a difference.
New spark plugs (or a change to a different type) can make a difference.
Check to see if your MAF sensor and aircleaner are clean.
Check to see if you're ingesting oil thru the PCV into the intake manifold.
Getting your BEN's closer to 1.00 causes a change in airmass which changes the cells looked up in the spark tables, and sometimes this cures knock.
Knock sensors have been known to deteriorate over time and falsely knock.
Joe
jsttry
May 20th, 2007, 02:55 PM
Would appear to be knock. Try logging the other spark PIDs to see if its burst knock or something else possibly.
NAH
May 21st, 2007, 10:15 AM
NAH,
That KR might be real...
It has a sawtooth shape and coincides with load (TP, MAP, g/s, g/cyl).
Your timing is already low at 10° or less and your AFR is sufficiently rich at 10-11 in the region where knock is shown.
Sounds like it's inaudible.
It's hard to say...
You may have to try some octane boost to see if it makes a difference.
New spark plugs (or a change to a different type) can make a difference.
Check to see if your MAF sensor and aircleaner are clean.
Check to see if you're ingesting oil thru the PCV into the intake manifold.
Getting your BEN's closer to 1.00 causes a change in airmass which changes the cells looked up in the spark tables, and sometimes this cures knock.
Knock sensors have been known to deteriorate over time and falsely knock.
Joe
I logged GM.ASPARK (High/Low Octane Spark Scaler) & it's showing 100.
Plugs were changed recently (can't remember what they are though - will check.
Air filter was changed two weeks ago & I am running MAFLess.
Will look into oil thru the PCV into the intake.
As for the last two, ok & mmmn respectively.
I logged a lot at the weekend & haven't had time to scrutinise the results yet. My initial thoughts were to look for a pattern in the various values logged, but will post more once I've had a good look.
In the meantime, thanks for the replies :)
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