Puzzling Knock Counts
Thread Starter
Drifting
Joined: Jul 2014
Posts: 1,426
Likes: 46
From: Lynchburg, VA
Puzzling Knock Counts
I just datalogged a run on my new engine, and the knock counts steadily rose up to 128, which concerned me. I tried accelerating, decelerating, cruising in high gear, cruising in low gear, and nothing affected knock counts. Then as I was just cruising along, they instantaneously dropped to 2. The only change I can think of was that I turned on the AC 30 seconds or so before the counts fell. But after a while, without turning the AC off, they rose to 54 then dropped immediately to 0.
First off, why would the knock counts drop back down without any obvious change?
And second, how many knock counts are acceptable? I know that knock counts don't necessarily mean bad things, but I don't know how many are safe.
Pertinent info:
First off, why would the knock counts drop back down without any obvious change?
And second, how many knock counts are acceptable? I know that knock counts don't necessarily mean bad things, but I don't know how many are safe.
Pertinent info:
- '90 6-speed coupe
- 383 stroker
- Ostrich 2.0
- New knock sensor
Burning Brakes
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Sometimes a knock sensor can be sensitive if not torqued to proper specs. The main concern is that it is not retarding timing because of false sensitivity. Can you attach the datalog.
Thread Starter
Drifting
Joined: Jul 2014
Posts: 1,426
Likes: 46
From: Lynchburg, VA
I was certain to torque it exactly to spec (I think 14 lb-ft).
Here's the log:
http://www.filedropper.com/8615run5
Here's the log:
http://www.filedropper.com/8615run5
Burning Brakes
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Your Datalog indicates you have an "Error Code 42: EST Monitor Error" This is for Electronic Spark Timing . Your Datalog shows a lot of Spark Retard occurring. I would investigate what is causing Err42 first and then go for another Datalog.
Thread Starter
Drifting
Joined: Jul 2014
Posts: 1,426
Likes: 46
From: Lynchburg, VA
Okay, I think the error 42 was from not disconnecting the battery after setting the timing.
Also, the issue with high knock counts seems to have gone away. Turns out my dad mixed up the #2 and #4 spark plug wires, and after putting them in their correct places I only got 26 knock counts on a 25 minute run.
Is 26 acceptable? Here's the data log.
http://www.filedropper.com/81015run6
Also, the issue with high knock counts seems to have gone away. Turns out my dad mixed up the #2 and #4 spark plug wires, and after putting them in their correct places I only got 26 knock counts on a 25 minute run.
Is 26 acceptable? Here's the data log.
http://www.filedropper.com/81015run6
Burning Brakes
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Yes way better. You still have some spark retard during WOT. Here is a list of the events:
Rec# 4233, WOT, 3000 RPM, 5.6 Deg Spark Retard
Rec# 4639, WOT, 3375 RPM, 4.2 Deg Spark Retard
Rec# 5088, WOT, 3000 RPM, 4.6 Deg Spark Retard
Rec# 5188, WOT, 3150 RPM, 6.7 Deg Spark Retard
Rec# 5822, WOT, 2975 RPM, 2.6 Deg Spark Retard
Rec# 7021, WOT, 3100 RPM, 6.9 Deg Spark Retard
Rec# 7550, WOT, 3300 RPM, 7.7 Deg Spark Retard
Rec# 8018, WOT, 3950 RPM, 3.3 Deg Spark Retard
You should try and correct this area in the Tune.
Rec# 4233, WOT, 3000 RPM, 5.6 Deg Spark Retard
Rec# 4639, WOT, 3375 RPM, 4.2 Deg Spark Retard
Rec# 5088, WOT, 3000 RPM, 4.6 Deg Spark Retard
Rec# 5188, WOT, 3150 RPM, 6.7 Deg Spark Retard
Rec# 5822, WOT, 2975 RPM, 2.6 Deg Spark Retard
Rec# 7021, WOT, 3100 RPM, 6.9 Deg Spark Retard
Rec# 7550, WOT, 3300 RPM, 7.7 Deg Spark Retard
Rec# 8018, WOT, 3950 RPM, 3.3 Deg Spark Retard
You should try and correct this area in the Tune.
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