Hi, my friends and I worked on my 350z last weekend and we installed a new JWT popcharger, z tube and a z1 plenum spacer. Took us 3 hours. It was a good experience for us. Anyways, when we started the car up after we were done, everything was normal. No Check Engine Lights, nothing. We even forgot to unplug the battery and reset the Chip. So we took it for a spin. We noticed that the car bogs and it vibrates slightly while pressing on the gas. I can feel the vibration from my feet to my steering wheels. It bogs and does the vibration only after when the engine is warmed up and 1-3.5k RPM. Idk if they is bad or not. What could be the reason this is happening?

 

this

 

wow i only have one of these what kinds of z u got

 

Driver's ed teachers are using Z's now, eh?

 

This is typical.

Members often add bolt-on mods, and that car runs worse than before. $300 later you have an extra 3 peak horsepower, but the car runs like crap. There is always a tradeoff.

 

Oh man this is bad, I don't know where to start.

 

You guys unleashed so much horses that they are so giddy and wanna get up and GO... thats it.

 

Lmao quite a bit of win here! But 2nd post will help ya OP :P

 

Unplug the battery over night.





Thats not oil leaking, its just engine sweat from all the horse power you got now

 

Did someone mess with the MAF sensor?

 

vacuum leak

 

and/or hitting the strut bar

 

-How much clearance do you have between intake manifold and strut bar?
-Any codes/CEL?
-Check for vacuum leaks?
-Does the vibration occur when stopped and revving the engine, or only when the car is under load (ie. driving)?

 

No cel. Um idk clearance but we bolted the strut bar down pretty good
didn't overtighten anything. Vibration happens when stopped and pressing the gas. It vibrates untill 3-4 then it stops. I'm gonna try a battey reset and check for vacuum leaking first

 

"You bolted down the strut bar pretty good".....BUT do you have clearance under strut bar??

 

Try the battery reset, and check the clearance between the strut bar and plenum. It's common for the strut bar to need spacers once a plenum spacer is installed. If the engine is touching the strut bar, it'll cause vibration.

Not sure if it's a vacuum leak since as RPM increases, so does vacuum which should make the leak worse. I may be wrong... Haven't dealt with a vacuum leak in ages.

EDIT: Also, is the idle at the correct setting or is it high? low? fluctuating? If the idle is normal, that's another thing that says it's not a vacuum leak.

 

Ya. We used the o rings spacers z1 provided. Idle is normal. It fluctuate 750-1rpm. I will try a battery reset this week. Thanks for all the help!

 

Fluctuating idle is not normal. Idle should be steady. If you've got a fluctuating idle, you likely have a vacuum leak.

Unless you mean the idle will sit steady at either 1k RPM OR 750 RPM. That's normal. When I say fluctuating idle, I mean this:

http://www.youtube.com/watch?v=V13-JMhsNzg

 

Like aforementioned:

Unplug battery, press the firmly down numerous times to get all power out of car
ECU reset
Throttle Body reset
Verify you have no vacuum leaks
Verify you hooked everything up correctly

The only personal experience I have with this: When I installed my MD 5/16 spacer, I also changed the spark plugs. I put everything back together properly (or so I thought). I did the ECU reset and the TB reset, but when I would drive the car would misfire, jerk, and make loud popping noises. Turns out I hooked up one of the ignition coils to the wrong labeled harness. I don't know if that helps

 

^^What s/he said. As a side note though a quick way to drain the system reserves is unhooking both terminals and touching the wires together.