babadudu

HI all,

I i own a 2003 automatic touring 350z. I have had this problem for quite some time now...

sometimes, I feel a short burp while constant accelerating , it feels like when you suddenly take your foot off the gas pedal , then step on it again...

if anyone could help it would be great...

because when I told the service about this problem, they said they cannot find the problems.

97supratt

iTrader: (61)

Then stop giving it too much soda!

XV8DRVR

I have an 04 and it does the same thing...can't figure it out.

97supratt

iTrader: (61)

Could be a misfire.

cracka350z

iTrader: (6)

mine mini-farts while idling

XV8DRVR

Wouldn't that throw a CEL though?

Cannysage

iTrader: (29)

Mine only burps after a nice meal.. such as mustangs, acuras and hondas

6swhite350z

burp.. as in backfire?

up2nogood

mine too

XV8DRVR

It's not a backfire, it's like when accelerating it hesitates for a second, like the original poster said, it feels like you took your foot off the gas for a quick second then began accelerating again.

Cozmo

i think you're feeling it shift lol

saberphx

iTrader: (5)

bahahaha +1

Aggro_Al

If it happens in 1st, 2nd or the low end of 3rd gear, it's torque multiplication. It feels like you let off the gas but you didn't. Torque is actually multiplying at an accelerated rate until the torque converter couples. The tranny is creating more torque than the engine is outputting. After it couples the transmission can no longer torque multiply and it feels like you slowed down slightly. If it happens in the high end of 3rd gear, 4th or 5th, it's the mechanical clutch locking the transmission. The tranny can no longer torque multiply or adjust torque when it's locked. Instead of being allowed to vary the gear ratio, the 5AT is locked into a fixed gear like the 6MT by a mechanical clutch.

XV8DRVR

Uh, I don't have an automatic and it happens at different points in the powerband and different gears.

Aggro_Al

In the 6MT there are several things that can cause it to pulse, things like the clutch disengaging/re-engaging can cause it "burp". Since, you manually add or remove the engine from the rest of the drivetrain the load change can cause it to "burp". Also, in the RPM range you are driving in, a slight change in the throttle may cause a pulse. The 6MT uses a weighted flywheel to help smooth out those pulses. The heavier the flywheel the less significant those pulses are but it is harder to accelerate. A lighter the flywheel can accelerate faster but your pulse swings will be more significant and more often.

If you're 6MT is experiencing lots of "burps" under normal conditions and you haven't modified it you need to take it in to get checked out.

Fletch69z

iTrader: (50)

Probably back pressure. Mine used to do it when I had the stock exhaust which is pretty free flowing, but after changing to straight through exhaust I get back pressure pops pretty frequently.

roast

iTrader: (2)

If it happens regularly then I guess that rules out bad gas. Probably not a problem with plugs or wires either? Have you cleaned out the air filter box lately? It sounds more like a fuel delivery or timing problem. It could be anything. Take it to the dealer if you can't get to the bottom of it.

XV8DRVR

Hmmm...all good points. I'm running a JWT intake, perhaps it's time to clean it. The clutch/flywheel are stock but I think it's almost time to replace the clutch (50k miles) so perhaps that has something to do with it as well...

roast

iTrader: (2)

Definitely. Clean it and see what happens. I change filters and clean my stock airbox regularly.