i30 Owners Club

Rev needle - foot off gas and still moving

eye30 · 12 · 5794

0 Members and 1 Guest are viewing this topic.

Offline eye30

  • Global Moderator
  • *
  • HOS BOSS
    • Posts: 27,385

    • england England
      Wirral

  • Wirral, UK. - 1.4 Petrol Active - Aqua Blue
When driving take foot of gas the RPM's will drop. (Normal engine function).

However, the RPM needle does not drop to idle RPM but will hovers just above 1000 rpm.

It doesn't drop to below 1000 rpm at any point whilst moving.

It only drops to below 1000 rpm when stopped.  It then idles around 8/900 rpm.

Anyone else noticed this?
  • 1.4 Petrol Active I'm no expert, so please correct me if


Offline Shambles

  • Admin
  • *
  • Retyred @ Last
    • Posts: 43,370

    • england England
      Manchester, UK
    • i30 Owners Club
Isn't this what some call the anti-stall feature?

Mine behaves exactly the same. When stopped at lights, the revs stay at 1000rpm for about 5 seconds then drop to around 800. When in gear and moving, around 1100
  • Ioniq MY2018 SE Premium Hybrid in Polar White with added oomph


Offline Lakes

  • V.I.P
  • *
    • Posts: 6,412

    • au Australia
      Deep south coast, New South Wales
the i30 uses fly by wire throtle, just because you put your foot down or take your foot off, does not mean the throtle at the fuel delivery will imitate you. it's all computer controled. a lot of new cars and motor cycles use this type of throtle now. i like it now but when i first started useing it with my ford falcon, i did not like it, but got used to how it works and love it now, with the ford they downloaded upgrades and the ute felt like it had more power.
cheers


Offline Thumper

  • 5th Gear
  • *
    • Posts: 583

    • au Australia
      ACT
Let me guess, you only notice this when it is very cold outside?  8-)

The hotter it is, the quicker the RPM's will come back to normal (700-800rpm) for idle.

Yesterday, 36 degrees C, idle drops back very quickly once everything is warm.

During winter here (-8 degrees C) idle will hang around 1,000rpm for a while (Up to 2 minutes) before slowly dropping down.

I believe it's to make sure the catalytic converter (Opps, I mean Diesel Oxidation Catalyst) remains hot and effective.


Offline bumpkin

  • Top Gear
  • *
  • Keeping it in the family!
    • Posts: 8,022

    • scotland Scotland
      Aberdeen
The petrol is much the same guys, I can get mine to drive off out of my drive without touching the loud pedal first thing on a frosty morning.
  • Kia Sportage 3, 1.7 CRDi EcoDynamics


Offline eye30

  • Global Moderator
  • *
  • HOS BOSS
    • Posts: 27,385

    • england England
      Wirral

  • Wirral, UK. - 1.4 Petrol Active - Aqua Blue
Quote from: "Thumper"
Let me guess, you only notice this when it is very cold outside?

No. It happen all the time. Hot/cold/rain/snow.
  • 1.4 Petrol Active I'm no expert, so please correct me if


Offline Shambles

  • Admin
  • *
  • Retyred @ Last
    • Posts: 43,370

    • england England
      Manchester, UK
    • i30 Owners Club
Quote from: "eye30"
Quote from: "Thumper"
Let me guess, you only notice this when it is very cold outside?

No. It happen all the time. Hot/cold/rain/snow.
Hey eye30.. where the hell do you get the "Hot" bit from  :?
  • Ioniq MY2018 SE Premium Hybrid in Polar White with added oomph


Offline bumpkin

  • Top Gear
  • *
  • Keeping it in the family!
    • Posts: 8,022

    • scotland Scotland
      Aberdeen
Mebbe it's his wife :?:  :oops:
  • Kia Sportage 3, 1.7 CRDi EcoDynamics


Offline eye30

  • Global Moderator
  • *
  • HOS BOSS
    • Posts: 27,385

    • england England
      Wirral

  • Wirral, UK. - 1.4 Petrol Active - Aqua Blue
Quote from: "Shambles"
Quote from: "eye30"
Quote from: "Thumper"
Let me guess, you only notice this when it is very cold outside?

No. It happen all the time. Hot/cold/rain/snow.
Hey eye30.. where the hell do you get the "Hot" bit from  :lol:

Oh sorry missed windy off the list. :oops:
  • 1.4 Petrol Active I'm no expert, so please correct me if


Offline LuciferDarklord

  • 5th Gear
  • *
    • Posts: 610

    • au Australia
      Bindoon, W.A.

  • Bindoon, Western Australia.
I reckon its to do with vacuum boosted braking system.  Diesels do not have manifold vacuum, so the vacuum for the brakes is generally supplied by a pump fun off the back of the alternator.  While you are moving, the computer has the engine revs a little higher to keep a good supply of vacuum to the brake booster.  Not sure on this but I think it may be the case.


Offline Thumper

  • 5th Gear
  • *
    • Posts: 583

    • au Australia
      ACT
It's actually a pump that runs off the timing chain/cam, on the battery side of the head. (Tube runs to the turbo and to the booster)

When you take the big black cover off the top of the engine you'll see what I am talking about.  8-)


Offline LuciferDarklord

  • 5th Gear
  • *
    • Posts: 610

    • au Australia
      Bindoon, W.A.

  • Bindoon, Western Australia.
Thanks Thumper.  I'm reluctant to take the cover off, I might get tempted to tinker.  Still the same principle at play with the engine revs tho I think.  Could have other reasons too but this would be a major factor in the ECU logic.


Unread Posts

 


SimplePortal 2.3.5 © 2008-2012, SimplePortal