wierd noise/performance when in mid range rpms

[leoni62486]

ok so my z, like sometimes when i would go wot, when it would get to about ohhh if say around over 3k and up, you could feel the engine like sputter almost or like misfire or something, andu can hear it, its really wierd, still climbs and goes really fast u kno, but when its gets in the higher rpm range it does this like its i dunno its really hard to explain, otherwise it runs very very good and smooth under normal driving, ONLY when im wot???? i dont get it, now theres no wierd noises u kno comin from the motor it self whe nits idling or anything, and sometimes it doesnt always do this to me....im stumped, now i dunno when the last time it had a tuneup, or new plugs or what not, thats what i could only think of, OH and i tried fuel injector cleaner thinkin that might be it, nope it wasnt..what do you guys think from this,

p.s. if there is anyone in my area, NW indiana chicago, lemme kno maybe u could come out and ill show ya what it does, much easier to see in person than explain.........

thanks guys

[leoni62486]

also mind, i do have, the LM exhaust, lid, bellows, k&n, sooo i mean i dont kno if that matters but...yeah

[Sarge]

How is your PCV? Got any oil in your throttle body? What do your plugs look like...what condition are your plug wires? What octane of gas you running?

[leoni62486]

pcv? i dunno....plugs i havent taken the out or anything tahts what i was thinkin could be causing it, and gas i had been runnin 87 i kno i kno but as much as it is out here lately ive put that in alot lately like havent put 93in her in awhile.....

[Sarge]

YOu just diagnosed your car man...
Replace the PCV....new plugs and wires..tune it...and get 92/93 octane in there....that is what it is tuned for...it is probably pulling timing like a big dog cuz of kr....

[leoni62486]

ok i kno im gonne sound like an idiot but yeah im still new tothe whole in depth modding and parts and abbreviations here..but what is my pcv?? haha i might kno just not on top of my head right now, also what brand plugs/wires would u reccomend (sp?) and yeah im gonna def start puttin the93 in her....

[Sarge]

Definition: The Positive Crankcase Ventilation valve is an emissions control device that routes unburned crankcase blowby gases back into the intake manifold where they can be reburned. The PCV system is one of the oldest emission control devices, and also one of the most beneficial. Besides totally eliminating crankcase emissions as a source of air pollution, the constant recirculation of air through the crankcase helps remove moisture which otherwise would cause sludge to form. Thus the PCV valve extends the life of the oil and engine. The PCV valve requires little maintenance. The valve and filter should be replaced somewhere around 30,000 to 50,000 miles (see the vehicle owners manual for service intervals).

I like them NGK 55R's for the LS1

[leoni62486]

alright thanks sarge, greatly appreciate all the advice, and ill have to go shop for a pcv here soon and get the plugs n wires....thanks again

[Capster78]

I might also check your fuel filter too if it hasent been changed in awhile.