PJG1173
03-09-2020, 06:38 AM
Guys, I recently boosted my truck. I have been chasing knock around for a while now and I though I had it licked last year, but with the latest upgrades to my truck am chasing what i believe to be false knock.
A little back story...
so last year I started to get a check engine light. pulled the codes and it was for the knock sensor. looking at it I found where the steering shaft had chaffed the sensor wire (body lift changed the angle of the steering right next to the KS). I moved the sensor to the drain plug at the bottom of the block, extended the sensor wire, and left the old sensor in the head. I did a data log to make sure that everything was good. Nope. KR at WOT. I have been running about 34* @ 100KPA WOT timing for the last 7 years or so and no indication on the plugs that there is any detonation. I rerouted the sensor wire back to the old KS and same thing KR at WOT. I replaced the KS on both sides of the motor still KR, I bought a can of concentrated race gas and upped the octane to 97 still had the same KR, so I started pulling timing until the KR was gone. I ended up with 19* timing a 15* reduction but there was no KR in the logs and had been fine until I slapped a turbo on it last weekend. I re-scaled my VE and spark tables for 2 bar MAP, I used the info from this thread http://www.gearhead-efi.com/Fuel-Injection/showthread.php?4552-Problem-adding-MAT-to-0D-TBI-7427-Not-pulling-timing and his other one for the template for my tune. one heat range colder plug with .032 gap. long story short I have been pulling timing to the point I don't think there will be any left to pull even in the non boost areas. I went for a test drive earlier today and had KR all over the place so I stopped by a buddies shop to fix my exhaust hanger (thinking that was the cause of my false knock). I pulled timing and added fuel to the VE table. I had even more KR. How is that possible? also my logs and histograms are showing over 20,000 degrees of spark under boost. I am at my wits end figuring this out. any one with some ideas? attached are my logs the adx modified for my setup, the bin (don't laugh its rough), and the xdf i used from 96lt4c4 thread. my thoughts on possibilities:
-bad coil 10 year old Street fire
-bad Crane HI6S
-Bad ignition control module (replaced distributor with autozone distributor when I did the MPFI swap at least 5-6 years ago).
A little back story...
so last year I started to get a check engine light. pulled the codes and it was for the knock sensor. looking at it I found where the steering shaft had chaffed the sensor wire (body lift changed the angle of the steering right next to the KS). I moved the sensor to the drain plug at the bottom of the block, extended the sensor wire, and left the old sensor in the head. I did a data log to make sure that everything was good. Nope. KR at WOT. I have been running about 34* @ 100KPA WOT timing for the last 7 years or so and no indication on the plugs that there is any detonation. I rerouted the sensor wire back to the old KS and same thing KR at WOT. I replaced the KS on both sides of the motor still KR, I bought a can of concentrated race gas and upped the octane to 97 still had the same KR, so I started pulling timing until the KR was gone. I ended up with 19* timing a 15* reduction but there was no KR in the logs and had been fine until I slapped a turbo on it last weekend. I re-scaled my VE and spark tables for 2 bar MAP, I used the info from this thread http://www.gearhead-efi.com/Fuel-Injection/showthread.php?4552-Problem-adding-MAT-to-0D-TBI-7427-Not-pulling-timing and his other one for the template for my tune. one heat range colder plug with .032 gap. long story short I have been pulling timing to the point I don't think there will be any left to pull even in the non boost areas. I went for a test drive earlier today and had KR all over the place so I stopped by a buddies shop to fix my exhaust hanger (thinking that was the cause of my false knock). I pulled timing and added fuel to the VE table. I had even more KR. How is that possible? also my logs and histograms are showing over 20,000 degrees of spark under boost. I am at my wits end figuring this out. any one with some ideas? attached are my logs the adx modified for my setup, the bin (don't laugh its rough), and the xdf i used from 96lt4c4 thread. my thoughts on possibilities:
-bad coil 10 year old Street fire
-bad Crane HI6S
-Bad ignition control module (replaced distributor with autozone distributor when I did the MPFI swap at least 5-6 years ago).