Running Rough On Idle

[Sss107]

Hi all, hope you can help. I've done a lot of searching already in the forum and now quite informed. I have a 182 and drives very well. However idle is awful, really awful!! (never stalls but is very lumpy and the whole car judders) and I am trying to hunt down the culprit. The needle moves alittle occasionally but is fairly steady. On start up, it sits around 1200 when could then reduces to 850 and becomes lumpy. 'Thump...thump...'. It is perfect when given some revs.

I appreciate that the juddering is emphasised by the KTEC mounts I have but this is definitely not normal.

Spec: Clio 182. Cat back exhaust. RsTuner. 98 Ron Map. KTEC mounts. Dog mount recently replaced.

I have done the following:

Ran diagnostics which said injector 1 and post cat lambda sensor.
I have replaced both the pre and post cat lamda sensors.
Replaced injector 1.
Swapped the coil pack with another one I have.
Swapped HT leads for another used set.
Swapped Map sensor for another used one.
Cleaned throttle body.
Spark plugs changed for Genuine NGK as per Renault.
Cam belt/auxilary belt and tensioner replaced 450 miles ago.
Checked timing and it is 100% perfect - was checked by Renault Specialist.

There are no codes now. Idle is still awful and I want to avoid throwing parts at it!
Would a coolant temperature sensor affect it?

Any help is very appreciated.

 

[LeeRS]

A lot of them are like this. Mine is too.
Runs fine but just judders on idle.

 

[smith647]

Don't waste any more money on part just raise your idle speed.. It's too low, bring it upto around 1000rpm when hot.

 

[Sss107]

Don't waste any more money on part just raise your idle speed.. It's too low, bring it upto around 1000rpm when hot.

How do you raise the idle speed?

 

[smith647]

The idle speed usually gets adjusted by the guy mapping your car and he'll adjust the speed to suit. Have you still got the RSTuner after doing the 98ron map? You should be able to alter the idle speed using that device.

 

[LeeRS]

I thought you could only adjist the idle on the ph1. Or am i jist making that up?

 

[DaveDreads]

If you've got the 98ron map it should be idling at 950 when warm not 850, plus it should have sorted out the lumpy idle, i've got exactly the same mods as you and mine's smooth as silk. (relatively speaking)

 

[Sss107]

If you've got the 98ron map it should be idling at 950 when warm not 850, plus it should have sorted out the lumpy idle, i've got exactly the same mods as you and mine's smooth as silk. (relatively speaking)

Sorry I'm a newbie.. How do I check exactly the idle figure with RST? (My mate checked it somehow) And can I manually adjust the idle? I will admit that the map did smooth it out a bit but not great!

 

[rctempire]

Presume you have already cleaned the throttle body?

 

[DaveDreads]

Sorry I'm a newbie.. How do I check exactly the idle figure with RST? (My mate checked it somehow) And can I manually adjust the idle? I will admit that the map did smooth it out a bit but not great!

The 98ron map idles at 1100rpm on cold start, then drops to 950 when up to temp, the other way of checking is seeing where your rev limiter is in each gear, but the idle test is less stressful on the engine.

As for manually adjusting the idle, this thread is the first time i've ever heard it mentioned, but seeing as the throttle is drive by wire (not physically connected to the accelerator) I highly doubt it's possible.

 

[Sss107]

Presume you have already cleaned the throttle body?

Certainly have.. Made no difference but good for the maintenance!