Pausing at 1500 RPM on Deceleration

[shaktastik]

My first post be gentle

 

Is it normal that when revving my car on neutral gear either driving or parked, the RPM gauge pauses for a 1 sec on its way back to 1500 RPM. It doenst do this when in gear with clutch down.

Can someone try this and advise if theirs do the same please.

My car is a 2008 GT 313 with typhoon air intake and cobra exhausts.

And if its normal can someone explain why its doing this please.

There is a video showing what I mean on youtube

 

Thanks in advance.

[steve916]

Hi and welcome

Mine did this once. I carefully removed the MAF sensors and gave them a clean. They may not look dirty but get some proper aerosol cleaner and give them a good squirt being careful not to touch the insides.

[shaktastik]

Thanks for your quick reply Steve916. I have done that yesterday but same thing. Does your car not pause when in neutral?

Edited November 4, 2015 by shaktastik

[Richf]

Are you saying it pauses AT 1500rpm like in the video if so thats normal

 

I assume you have you tried the throttle body relearn ?

[steve916]

Here's mine

 

[shaktastik]

Hi Rich yes its pausing like on the video. And I did the relearn.

Steve, is your gear knob on neutral when you did that? and thanks for your effort to post a video

I will post my video when get home tonight.

Edited November 4, 2015 by shaktastik

[steve916]

Yep

[karlh]

The ECU cuts fuel when rpm is over 1800 and there is no load on the engine. Fueling is turned back on at 1500 rpm, which porbably explains the hesitation you're seeing. Here's the text from the service manual:

 

"If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed. Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled."

[davey_83]

Anti stall, most petrol do it

[shaktastik]

That explanation makes sense to me. I'm glad this is not a fault. Here is my video I took now. It was doing it on neutral and also on gear. Possibly like you explained there was no load.

 

[shaktastik]

And if it should be pausing at 1500-1800 RPM why is Steve's car not doing it?

What mods do you have Steve?

[Mrzed]

ITS NORMAL.......TRUST ME ITS NORMAL !!!!!!

[steve916]

And if it should be pausing at 1500-1800 RPM why is Steve's car not doing it?

What mods do you have Steve?

 

Cobra exhaust and HKS panel filters. That's it.

What's interesting here is that a few months ago I posted up an almost identical question to your OP. I was told, "It shouldn't be like that. Get the sensors cleaned. That'll sort it"

[shaktastik]

I've seen your post Steve and I tried cleaning the MAF like you did but made no difference so I thought I will ask 350z owners for their opinion.

[steve916]

I've seen your post Steve and I tried cleaning the MAF like you did but made no difference so I thought I will ask 350z owners for their opinion.

 

No probs mate. I couldn't find my original post earlier, but all the answers on this thread do make sense.

I too now wonder why mines not doing it lol

[Richf]

My HR did it but Jez at H-Dev assured me it was normal . I had a few idle problems with mine and seem to recall they can be troublesome, I read some horror stories on US forums about people who had tried to clean the throttle bodies so left it alone , repeated pedal dances helped but the idle speed would rise over time on mine

[shaktastik]

Had an answer from a youtube garage confirming what you all being saying:

 

"We did look in to your question, and our product engineer offers this: It’s normal for the car to do this, when you’re decelerating the fuel/air gets cut off from the engine but it’s programmed to turn on again at around 1500 RPM so the engine doesn’t stall. Hope that's helpful. Thanks for watching!"