Lumpy running 172 when cold

[b33fy172]

Hi all,

Picking up another ph1 172 tomorrow, it has a slight problem when cold seems like its in limp mode and really struggles to rev, but once warm this disapeers and is 100% running normal.

any help would be apprciated.

 

[track-tor_boy]

i think there all generaly alittle umpy on idle and just after start up mate!! also think theresa restriction on the revs aswell until engine is warm, but dont quote me on that

 

[b33fy172]

No theres definately something not right this is the third RS I've owned, it feels like limp mode, but then just clears up once warm.

 

[b33fy172]

Anyone?

 

[Dave.]

Mine has done this when lambda was knackreed, pre cat lambda

 

[b33fy172]

Ok, cheers Dave I'll check that, think it had a lambda not so long ago. Is it possible for it to fail so soon?

 

[gtrnav]

Has it been chipped? That can cause lumpy idle, particularly when cold. Mine is always uneven!

 

[Daniel]

Coolant temp sensor? (I've got a spare one you can have if you want it)

Lambda?

 

[b33fy172]

Has it been chipped? That can cause lumpy idle, particularly when cold. Mine is always uneven!

Not as far as I know, but its pretty much undrivable when cold its not just a lumpy idle, there is something not right!

Coolant temp sensor? (I've got a spare one you can have if you want it)

Lambda?

Cheers Dan I'm gonna look at it for myself later, only info I have is from my friend as when he took me out in it yesterday it was warm and no problems.

 

[mishmish]

mine does that too
thought its the way it should be since once warm its running perfect..

 

[b33fy172]

I give up.

 

[b33fy172]

Right I've just picked up the car, when cold theres no power no ability to rev just bogging down, then bang! exhaust pops does this a couple of times then drives fine. I've been given a knock sensor with the car which I'll fit on the weekend. I'm assuming thats just a straight swap?

Also Its a Y reg Ph1 with a twin barrel cat, would it have two Lambda's or just the one?

 

[gtrnav]

Just the one lambda sensor.

 

[Laine_16v]

Wouldnt waste your time changing the knock sensor, it wouldnt be causing what you are describing.

 

[b33fy172]

Wouldnt waste your time changing the knock sensor, it wouldnt be causing what you are describing.

Any idea what could be causing it then mate? Do you think it could be the Lambda?

 

[gtrnav]

You could spend a fortune trying to guess what is wrong with it and trying new parts. Take it to someone who knows what they are doing, and get the fault properly diagnosed. Lots of good Renault Specialist garages on here.

 

[gez 172]

iv'e been in this clio and i can also say its not the usual lumpy idle. The car idles around 500-600rpm and you cant drive it until it clears.

 

[Daz_RT_04]

My ph1 done it to.

Plugged it in to find Air temp sensor was knackered.

Had some fun times with the boggy from cold though, drive it a lil bit...let off and tap the throttle *pop pop pop* lol

 

[b33fy172]

My ph1 done it to.

Plugged it in to find Air temp sensor was knackered.

Had some fun times with the boggy from cold though, drive it a lil bit...let off and tap the throttle *pop pop pop* lol

Thats exactly it! when cold no power no revving foot down nothing, let off *Bang* then once warm absolutely fine.

 

[JoedotwasT5phy]

Air temp sensor would be my guess. Then the Lamda.

 

[b33fy172]

Air temp sonser ordered, I'm gonna fit the Knock sensor as its brand new and I'm gonna order a new Lambda sensor too!
Hopefully sort it right out.

 

[Daz_RT_04]

The air temp sorted mine fella

 

[Kevin172]

Mine is doing the same too. From cold i get a lumpy 30-40 seconds then pop she fires up and is fine from then on. ive just changed the air temp sensor today but still the same. Mine is a phase 1 on a 2000. will she have two sensors pre and post cat?

 

[npt]

my cup was very lumpy in the morning and spluttered about when using v-power, i can use any other high octane fuel now and it runs a lot better

 

[Kevin172]

Would you recommend using a 99 octane fuel for example? I've contemplated filling up on the good stuff but I wasn't sure if my 172 would benefit

 

[ADS_V6]

they all run crap from cold for a bit its normal,a remap helps it out

 

[imprezaworks]

The fuel imo won't help cure the issue. Unless the car has been mapped on the stuff you're not using but even then the ecu should re learn. I've had four and unless rs tuned or alike they have been a bit lumpy but not what you guys are experiencing

 

[Kevin172]

I'm
Sure it's my pre cat lambda that needs changing . I was just curious about the fuel to see how other 172's run on higher octane . Not related to my idle issue

 

[npt]

I only noticed my issue by accident, it used to be really poor in the morning and read on here they were all like that so never really thought more about it, then i noticed one morning it was a lot better, the only thing i could think of was fuel as i'd put in tesco 99 a few days earlier, so i put in a tenner of v-power again next time around and it slowly came back to being very poor when cold, i aint used v-power for a few months now and although its not perfect when cold it is miles better than it was before, i now use the BP ultimate/tesco99, its weird and can't see why it should make a difference but it does (weird frenchie)

 

[imprezaworks]

May have been previously mapped, maybe

 

[Kevin172]

Replaced my intake temp sensor , replaced my pre cat lambda. That cured my lumpy cold idle after the choke . Filled up with 99 Tesco jungle juice. Drove for a good week expecting my idle to improve. Tonight I was coming to the end of my tank full and the car started spluttering similar to my pre cat replacement symptoms then suddenly "pop" started idling so much better and driving better. Could it be my ecu settings changed or do they slowly change over the miles ??

 

[imprezaworks]

It would take less time for the ecu to re learn after a week and a full tank of fuel, I may be proved wrong.

 

[Kevin172]

Maybe . There was a mixture of 95 and 99 in there . I recon tonight it was mostly 99 . Cannot come any other conclusion as to why it's just changed the idle

 

[imprezaworks]

Keep trying the higher octane fuel for a few weeks and see how it pans out?