I searched and searched, but couldn't find anyone with this exact problem . . .

I've got an 08 manual ZR. I'm a very skilled stick driver, so please don't blame it on that.

If I'm in, lets say 3rd gear (though it seems to happen in 1-4) and I coast til the rpms are in the 1-1.5k range (above idle, but not above 1.5) then try to accelerate out of that range, the car bucks. Quite a bit. The slower I accelerate and the more gradual I am the less it bucks. And it doesn't buck as hard as if I had missed a gear or some stupid ****, but it's pretty obnoxious because I'm always at high revs to avoid it. Does anyone know what I'd need to replace to help combat this?

Or if it's something that everyone just has to deal with . . . or if there's something wrong with my clutch/transmission.

I should also note that my clutch in general is ****ing touchy as hell. Could that be causing it?

Thanks in advance

 

What mods do you have?

 

the HR's have known clutch issues, but to me this doesnt really sound like clutch, almost more like an air leak

 

^^^ Does sound like maybe a vacuum leak... noticeable at lower RPM's but not at higher/full throttle... But usually vacuum leaks are made obvious by a sporadic idle

 

Mine was doing that after the supercharger install. It was fixed by tweaking the tune. Johnny told me to go drive the car for a couple of weeks and come back with any notes, and this was one of them. He explained it to me as the car is running lean in that RPM range, then when the computer sees the lean condition, it automatically dumps fuel into the motor to compensate (feels like someone stabbed the gas pedal). Then if you hold it in that range, like idling thru a parking lot, it will just do it over and over. He told me all he had to do was add some fuel in that range with the tune and it would stop. I know it's got to be more technical than that, but he explains everything to me on a level I can understand.

 

Sounds like mine (sc/hr, after sc install) idling, low speed in a parking lot, etc. Runs like a champ otherwise, but does some "bucking" like the op describes. My Cipher logs don't show much really for that issue according to Stillen's main tuner Sam Camarillo. Since the car is running so strong in 91 oct. map #1 and 95 oct. perf. #2 map I don't worry about it; don't have vacume leaks. I wish that it was smooth while idle speeds, but to me no big deal. OP, hopefully it isn't a worse issue with yours and good luck with it.

 

When you say “bucks,” do you mean it feels as though you lost power for an instant and then immediately regain the power (so it feels as though it “bucks”)?

Spike

 

It can definitely be fixed in the tune. Johnny fixed mine. If you get tired of Stillen, contact jTran and see if they can help you out. I don't know how much he can do remotely.

 

^thanks for the info., but my UpRev is a locked license with Stillen and only they can access any tunes. Only other way is to buy a seperate cable; I will contact them again and mention the issue and most likely do a log or two and see what they may find.

 

Totally stock engine and transmission. And it's almost like the clutch engages then disengages. And if it's really bad, I can hear the clutch rattle.

 

the 'rattle' you describe is prob the flywheel chatter our cars are know for. what year is your car and miles....possible the clutch is shot and needs to be replaced

 

It does sound super similar to the chatter I get when the car isn't moving and engaging disengaging the clutch super occasionally. I think the clutch is toasted, but I took it into Nissan and they broke it open and said it was fine, and felt just like a stock clutch is supposed to feel. So I was looking into getting some aftermarket parts and wanted to know which ones would help get rid of this problem for good.

 

mine does this too but i have a single mass flywheel and exedy clutch, its normal i wouldnt worry about it, its a pain in stop and go but its just another upside to the z

 

I have this same problem occasionally in the morning but if I take my foot off the gas press in the clutch and drop it in gear again it won't happen I almost sometimes think it's just a sequence started by a light gas pedal foot IMO