tiffo60

iTrader: (2)

yeah if there is any metal clanking around under the hood it will be picked up as knock

custm2500

iTrader: (10)

There is nothing loose under the hood. I never hear anything banging around and she is compleatly stock.

I guess maybe I will put my stock tune back in and see if I still get some knock. If I don't, then I know I need to add fuel or pull some timing.

TXSZ66AVLANCHE

iTrader: (7)

Dump max fuel, roaming coal like a diesel is cool!

Is this a flexfuel?

custm2500

iTrader: (10)

No flex fuel.

I think I might double the fuel and see what happens! Thanks!

TXSZ66AVLANCHE

iTrader: (7)

Serious suggestion: check fuel pressure when the pinging is happening. Preferably with a pressure gauge.

1FastBrick

iTrader: (17)

Custm, what year is the truck???? I know some 99-00 had false knock issues.

Swap to the factory tune and log it to see if you have the same issue first.

tiffo60

iTrader: (2)

nonnieselman

iTrader: (10)

go to Holden crazy and find a 2002 2500HD tune.. OS is 12212156
flash that in, check gear ratio and stuff first..

gotta do a Full Flash tho!!!

see if it runs any different if the truck is still bone stock.

Last Call

iTrader: (4)

Post the log file and be sure to log intake air temp, coolant temp, rpm, speed, maf, g/cyl, spark in cylinder 1, kr, and commanded afr.

You need to exactly where the knock is happening before you can make any changes.

custm2500

iTrader: (10)

Well small update. I cut off the muffler today and ran pipe to the back axle so far. It seems to have helped the knock except for 80-90 mph. I didn't log and only used my torque scan on my phone but it seemed to agree very close with EFI live yesterday. I am still getting 6+ degrees at high speed but the 50-60 issue is gone on 5-7 pulls today. Does that make sense? Does that lead to anything being more of the possible culprit?