BLK02Z06

iTrader: (1)

I have an '02 Z06 that is falling off above 5400 rpm's. I had it on the dyno and I compared my dyno graph to other Z06 graphs. All the other dyno graphs showed the other Z06's pulling power up to 6400 - 6500 rpm's. Anyone have an idea of why I could be losing 30 - 40 hp up top? We pulled the pushrods and all of those were straight. Could it be the valve springs being weak or anything else I could check? I did have a code from the knock sensor... Could it be a bad knock sensor? Any help would be appreciated. I have one week of warranty left so I want to get everything checked out that I can.

Thanks in advance

Ferocity02

iTrader: (60)

Post the graph.

DWillTA

iTrader: (3)

If the power falls sharply then it could be valve float. You say you had a code from the knock sensor. What was the code exactly? Did you experience any KR on the dyno? Also a graph would be great.

Camaro99SS

iTrader: (4)

If it's running lean enough, the sensor may pull timing as much as it can but if it needs to pull more maybe through a severe lean condition, it may throw a code. I would hook a fuel pressure guage up the rail and check that first. It should be right around 60psi across the board. I have a hard time believing you have weak valve springs since you probably have low miles.

Jason

PREDATOR-Z

At WOT you'll never get 60 psi at the rail unless you have a booster harness.

BLK02Z06

iTrader: (1)

I taking it to the dealership and let them check out the valve train. I was picking up some KR on the top end and I was losing 2-3 degrees of timing. I think I'm getting valve float the way the graph noses off and with the KR. Thanks for the info. and I'll update after it's back from the dealership and back on the dyno. I'll get the graph next time. Thanks again