TPI-Formula350-

just wondering if the knock sensor will pickup an exaust rattle from the collector area? I did a WOT log and had a knock count of 17 and car was pulling 2 degrees timing.. After the pass I could feel and hear the exaust rattle

IROCThe5.7L

Yes it will. In my experience it did at least.

TPI-Formula350-

just did two more datalogs...I had no knock counts at idle but 8 knock counts and pulled 3* degrees when I shut the engine down. The other log had 11 KCs and 2.50 KR that all came in just after turning engine off 0 RPMs...

EagleMark

My experiance with Knock Counter would be YES! It is built to try and find just real knock counts but falls short.

Even the GM manual say if there is a intermittent/glitch. thought of failure to hit the block with a hammer. So that says they even know it will pick up other noises.

Ronny

iTrader: (1)

Mine does same. Could be my headers to dual ext. dual exhaust hitting unibody. roller rockers, aftermarket mufflers. Or others. I set retard to 1 degree in .bin... It was said a 4.3L KS is less sensitive? I may even disable.

EagleMark

Do you know anywhere, where knock sensors sensitivity or frequency is documented. The differance scould really help guys with certain engine mods or conversions.

Ronny

iTrader: (1)

I bought a new Polaris sled in 2005. KS was way too happy. Not detonation just too sensitive. Factory service bulletin suggested a nylon flat washer between block and sensor as a fix. Is not the GM sensor a push fit so that may not work?

EagleMark

Not sure? But some guys on here recomend an elbow on Knock Sensor... from what I have read in GM service stuff the sensor itself needs or is designed to be in water port, so it gets it reading of knock through coolant.

TPI-Formula350-

so I took the car in today and had all the rattles fixed. I did a few logs since and I'm still getting knock counts and timing retard. I had 21 KCs at WOT with 3* KR. Thats with only 29* total timing and 12.5 AF at WOT. I also am getting between 7 and 12 KCs every timing I shut the car off, is that normal? So I checked my accesories and they are not rattling and exhaust seems good so WTF? Engine is 11:1 so I think the 93 octane I run should be ok? Any ideas?? Thanks..

RBob

iTrader: (1)

The knock counts at key-off is normal. The knock filter is powered down immediately at key-off, while the ECM runs for 4 more seconds then shuts down.

Pull some plugs and check them for signs of detonation. Little black pepper flecks on the center porcelain. If present then so is real knock.

RBob.

TPI-Formula350-

The wot log from today had a few knocks at heavy part throttle and like 21 knocks at WOT from 1 st gear into second, with 3.40* knock retard. Just to make sure my understanding is correct. Total spark is in Tuner Pro(Spark Advance Table)+(Power Enrichment Mode Spark Advance)?? If so in the PEMSA i'm 4.92 at 2000 and 3200 and 5.98 4800. Then that added to the main spark table in row 208 @ 2000-3200rpms 20 to 22.15 making a total of 25-27* and 22-23.20(main table) from 3200-4800+ PEMSA 4.92-5.98 making the total timing in row 208(WOT?) 29*?? Way lower then the 36* total timing the engine was dyno broken in on out of the car. Also I see in the main spark table in rows 32 through 128 the 1800-4000rpm range the spark advance is 34*-29.88*, that plus the 4.92 of the PE mode spark advance would have my total spark between 39* and 34*? That 39* looks high to me if I'm figuring this out correctly. The AF looked good at WOT 12.5-13.2, I'm attaching the BIN...thanks for any ideas

JP86SS

iTrader: (1)

There is a load Vs Coolant modifier table at 10F->17A also.
It is named "Spark Correction - LV8 vs. Coolant Temp" in "Expanded 6E" XDF definition.

I see a selection bit to choose "LV8 or "alternate" .
Not sure what the purpose there is, looks to use a different scale.
Maybe someone could correctly clarify how that works.