animuL

iTrader: (3)

I did a search and found that several people have had this issue before but I dont see any definite answers. I never noticed this problem on my car before, but after installing the MS3 cam, when I start the car up it maxes out KR at 14* and very slowly decays. The car barely wants to idle until it gets the timing back. I've tried killing the Knock Sensors below 1600 RPM, added fuel, taken fuel out, and its always the same story. Car is a 98'

animuL

iTrader: (3)

Just verified on my old log files that this was not happening before. Stock cam = 0KR at startup, install an MS3 cam, chromoly pushrods, and new valve springs and bam, 14*KR at startup.

69LT1Bird

iTrader: (1)

post your logs and tunes files

animuL

iTrader: (3)

Attached tune and log

TAQuickness

iTrader: (28)

Sounds like valve train noise. Did you measure the PR's and lifter preloads?

animuL

iTrader: (3)

I did not measure any preloads, never knew I was supposed to I guess. I did follow the GM torque spec procedure for the rockers tho and used loctite. I also dont hear the valve train like I have on some other cars (Mustangs ). Thing is, if it was a noisy valve train, why would it only do it on startup? It gets a few ticks every once in a while at idle, but not much. I could see it if it got a few degrees of KR on startup, but 14*?!? Who knows, if the max KR value was set to 25* it might show that. I could also see this if it only hapened after the car sat for a while and all the oil drained off the rockers and such, but I can shut the engine off and immediately restart to see the same thing happen.

jimmyblue

iTrader: (11)

Are these original knock sensors or have they been replaced?
Maybe the cam just made idle more timing-sensitive. Any KR
problems in regular running?

animuL

iTrader: (3)

OK, I figured out my attempt to disable the knock sensors before was the wrong way to do it. I disabled them in non PE mode at lower MAP values and no more KR. It only sees a few ticks like 1* sometimes at WOT.