pwrtrip75

iTrader: (8)

99 vette on E85. Hp Tuners, MAF tune, I had advanced the timing a few degrees and I made a pass down the road and logged it to see if im getting any KR.

It logged "0" everywhere for KR but my timing histogram showed lower timing, like its reading my low octane table. ?? All across the scale it read about 5 degrees lower than what my high octane scale is set to.

Engine temp when logged was 195 degrees, IAT reached 95 degrees, no knock anywhere.. Why am I losing timing?

also zero codes.. appears to be running perfect. ?

SSpdDmon

iTrader: (10)

I had a similar problem with a buddy's car. Turned out to be burst knock retard. Check the burst knock delta and make sure it isn't so low that it's kicking in BKR (Spark Control, Spark Retard tab, BKR Enable Delta). I increased my delta so that it was .08~.06 grams/cylinder.

Also, check IAT spark alterations (Spark Control, Spark Advance tab, IAT Spark Base). Keep in mind, you will need to pull timing if intake temps are higher due to your location. The timing the engine should be running in 70* intake temps is not the timing it should be running in 100* temps.

If that doesn't make it obvious where the problem is, you should try to log all timing PIDs that would show where timing is being pulled. Then, you can back into it.

jimmyblue

iTrader: (11)

There's a whole rack of timing retard and timing advance PIDs you can
log to see why. Also look at Knock Learn Factor.

Old Geezer

iTrader: (3)

Am seeing the same thing on my LQ9...AIT's over 100* results in 0-5* of timing.
In looking at PE vs IAT, there's some serious timing being pulled.

sho-me speed

iTrader: (55)

Post your log and tune file.