Lumpy idle...

[EvoFq3o0]

Hey Guys

Had my pre cat lambda sensor replaced on Saturday and since my idle seems pretty lumpy even when warm. Its not settling and hovering around 1000rpm.

I'm pretty sure the car didn't come with uprated cams so can rule that out.

Also drinking petrol pretty quick and I'm not doing any great trips. when I last checked I had done 42 miles on a quarter tank.

Any ideas what this could be?

​

 

[icebergclio]

42 miles to a quarter tank! deep pockets required! mines lumpy aswell but i can get 300 miles out of it to fumes if i brim it. ive changed old plugs... a very dodgy set of leads and the coilpack for the sake of it. also checked over the fuel rail loom as its a problem where the loom rubs against the block and bares through the wiring which can cause an idle mis according to our local sparky. still got the miss though but it pulls like a train nevertheless so.... bum. if theyve done that to the lambda then surely somethings faulty with what theyve done especially with that fuel guzzle.... id be going back...

 

[EvoFq3o0]

Cheers, I'll check the loom as you suggested.

I was hoping not to spend anything for a while as it cost me £542 just last week apparently the service was done 4000 miles ago but no receipt just the stamp. So may have to dip into my pockets yet again.

I'll order a set of NGK pfr6e-10 plugs, would you recommend a after market panel filter? Coil pack has previously been replaced also just a question wether to get some new HT leads.

It was diagnosedjust last week and turns out there was no misfiring. wish there was a specialist near by. Id go and see Fred at BTM but it's a two hour drive and I'd end up coming away with the btm exhaust, decat and manifold.

 

[icebergclio]

ha ha i know what you mean mate. my leads were badly corroded and the fuel rail cover is the area that can chafe through the loom. i fitted a kn to mine 30 quid delivered from jjc raceandrally off ebay shops. reading up it could be an injector... ill have to get it fault read to be 100% sure but no eml lights? i bloody hate misfires... about 70% of cars ive owned have ended up with one aswell lol

 

[EvoFq3o0]

I'll check tomorrow hopefully not raining then. Do you get a nice note with the K&N? I did the RSTuner ron 98 map last week and only fault was the o2 sensor then got the eml the day after cleared it and came back the day after that, which I've had replaced with a brand new lambda sensor. I guess I can plug it in again but there's no lights.

I'm running Tesco's momentum 99 ron so no reason for that to be an issue.

​all in all everything that needs to be changed should have been done, Need a local expert me thinks

 

[icebergclio]

doesnt make any difference imo but kn are the best so they claim. no noise either. im fitting a ktec induction kit next week anyway so neither here nor there. i want to do the rs tuner map at some point aswell! how much did it cost all in? can you diagnose other faults ie airbags or is it purely for engine diagnostics? i run tesco 99 aswell

 

[EvoFq3o0]

Hmm probably leave the k&n then, will consider the ktec when I return from holiday. love the induction noise Well I bought the tuner brand new for my 1.6, that came with licence and map and delivery all in at £197

Then paid for license and map for my 182 which was £79

I know you can clear airbag faults, I think any error as long as it's picked up by the ecu.

Clubcard points ftw

 

[mattjk]

Check live data on o2 sensor. Revving on idle. You sure you dont have an air leak somewhere?

 

[EvoFq3o0]

Check live data on o2 sensor. Revving on idle. You sure you dont have an air leak somewhere?

Cheers Matt, will give that a go too. I haven't looked for an air leak to be honest just thought the garage would have checked over everything when it was in for diagnostics on Saturday.

 

[icebergclio]

good man. yeah the filter didnt do much... i was going to fit a ktec but i always go the sensible route and buy twice :-/ first lowering springs - coilovers now kn - ktec. money to waste ... oh yes. keep up the thread id like to see how this pans out

 

[Harbinger]

Rs tuner will sort the idle out it'll sit at a visual 1000rpm with minimal lumps

 

[EvoFq3o0]

No worries bud, Brought my rstuner to work so will run it later. will hopefully send lots of pretty graphs

Harbinger I did that map last week, Just went a bit iffy after having the lambda sensor changed.

 

[Harbinger]

They are lumpy in general, is the rev counter all over the place or is just a bit rough inside the car?

Mine rattles all over the shop and feels like it's going to fall apart but the counter itself and the engine are fine, I need to change the mounts which I really cba to do and that will sort it right out.

 

[mattjk]

Yeah what harbinger said is correct. First thing id do Is check intake bits.

 

[EvoFq3o0]

Hmmm wasn't so lumpy before though Harbinger :S

Taken a few screenies of live data etc

o2a by EvoFq3o0, on Flickr

o2b by EvoFq3o0, on Flickr

o2c by EvoFq3o0, on Flickr

o2d by EvoFq3o0, on Flickr

I'm no expert hence why I'm asking you guys for help so I really appreciate it, the front o2 sensor keeps fluctuating in voltage, see min and max values.

 

[EvoFq3o0]

Is anyone able to give any feedback regarding the images taken please?

 

[mattjk]

Not thats its much help but I can confirm the pre cat HO2 sensor looks healthy and functioning as it should. How does it drive as apposed to idle and engine lghts fault codes to lead a clue.

Check other things like engine coolant temp sensor also. check resistance with an avo when upto temp ill check what it is later if you need it.

What MPG is your onboard saying?

 

[EvoFq3o0]

Thanks for your response Matt, when driving its fine really, just feels more lumpy since the new sensor has been fitted but starting to think its normal after what a few others have mentioned.

Mpg was at 21.8 last I checked. I'm not 100% if this is normal as I've only owned the car for a few weeks. But was hoping to get around 35 mpg like most people state.

 

[Seoi-nage]

21.8mpg.... either you drive VERY hard or somethings not quite right.... :S

 

[EvoFq3o0]

Nope don't drive that hard at all, it's mostly shortish trips around town but no real reason for it to be so bad. hence me wanting to get it sorted

​I presume when you say very hard your meaning racing around every where? Not doing that just going up to 5th then cruising.

 

[Amos91]

Nope don't drive that hard at all, it's mostly shortish trips around town but no real reason for it to be so bad. hence me wanting to get it sorted

​I presume when you say very hard your meaning racing around every where? Not doing that just going up to 5th then cruising.

Does the temp gauge get to the middle fairly quickly and stay there?

Over fueling tends to be lambda or coolant sensor related from what I have commonly seen.

 

[EvoFq3o0]

I'd have to say around 6 minutes to get up, but does stay there. mind you I haven't been on any long drives since owning the car.

 

[mattjk]

Definitely got a problem at 22mpg

So to recap, tb cleaned, new lambda, checked coolant temp sensor. You could check your injectors also with an avo they should read 14ish ohms. Perhaps one is faulty and chucking too much fuel in

does it pull ok? timing could be out, unlikely probably electronic but worth chucking the idea out there. edit: if it was okay before then ignore that.

 

[EvoFq3o0]

Cheers Matt, new lambda sensor, apparently serviced and belts done at 57k now on 61k. just received full service kit so will get that re done. coolant temps fine. will need to clean TB yet and test injectors. pulls fine as far as I'm aware but again new to the car so would need someone who's used to 1*2 for a proper opinion.

Appreciate your help. will try and get TB cleaned plus injectors tested as soon as.

 

[Harbinger]

Race a pre- 07 Cooper S, you should beat it, that my general indicator of pulling ok.

the economy seems bad though, any clouds of grey smoke when you punch it? would be the first indicator of running rich.

​When was it MOT'd? does it have the emission scores?

 

[mattjk]

If you were nearby id come have a look lol. ahh sure timing will be fine then!

Do the TB yourself, very simple. screwdriver and 10mm socket brake cleaner and a toothbrush.

Injectors again easy, take off fuel rail guard, 2 10mm nuts. then unplug injectors and set avo to 20ohms and record what they are

Also what is the MAP sensor value with the engine off, worth checking too as that can effect fueling, should be roughly atmospheric

let us know how you get on.

 

[mattjk]

Forgot to say check tyre pressure too maybe bad idle is an unrelated problem

 

[icebergclio]

funny you should mention the cooper s scenario. had a cooper s pre 07 and a post 07 have a go at me at the same time the other day on the a50. smoked the pair of them lol which surprised even me. was the fuel con this bad before the lambda was changed? if not and looking at those rs tuner prints youd think it was the lambda that was fraggled :-/

 

[Harbinger]

funny you should mention the cooper s scenario. had a cooper s pre 07 and a post 07 have a go at me at the same time the other day on the a50. smoked the pair of them lol which surprised even me. was the fuel con this bad before the lambda was changed? if not and looking at those rs tuner prints youd think it was the lambda that was fraggled :-/

Really? You shouldn't beat a Turbo mini. I haven't anyway.

 

[EvoFq3o0]

Sorry not had chance to check most things yet due to work. I Have the MOT but no emission scores :/ There's no smoke to it. Pulls really well but again on comparison to either a cooper s or other 1*2 I'm not sure.

I know the Tyre pressures are fine, the fuel was pretty bad before lambda but worse after, but could also be due to the new tyres? Rainsports don't have the best economy rating.

Will try and check all the other things you guys recommended as of today I'm off work for 3 weeks

Might see if Jesus will have a quick look for me as I know he's in Bury which is up the road.

 

[Seoi-nage]

Does it smell rich when it's running?? Once up to full temp obviously.
​May sound daft but have you checked for any fuel leaks?