Clio 182 misfire under light/medium load

[Benjiman46]

As the title states! When I slam my foot down on the throttle, it has a little splutter then it goes.
At first I thought it was plugs, so I checked those and they're fine (all look the same, nice, light brown colour) So I checked all the leads, sprayed WD40 into the leads and replaced the coil pack. It's still misfiring.

It misfires the most under light to medium load ie setting off and cruising, but at WOT it's fine.

PLEASE HELP!

I've plugged in my RS Tuner and the codes are...

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[aucky]

O2 sensor?

 

[Benjiman46]

Would it cause it to misfire? I thought O2 sensor just affects MPG, I'm open to ideas keep em coming haha

 

[Chris_Beer]

By the look of your avatar, probably a fucked front lambda sensor lol. Check your plugs and leads, injectors, map sensor maybe or any air leaks

 

[DannyR]

Injectors and/or lambda

 

[bloke]

how long you had pops and bangs map on for?

 

[Benjiman46]

Over a year now mate

 

[bloke]

may well be valves/seats on their way out. could be worth checking voltage on the lambda and then check hydrocarbons if lambda checks out ok.

 

[Benjiman46]

Well I know the Lamda sensors need changing because of the fault codes, so should I try swapping them front to back? Wouldn't valve seats be an "all the time" fault rather than intermittent? I drove it all the way to my mum's house yesterday and it never missed a beat, but on the way back it started again. Feels like fuel starvation tbh and it pinks like hell if I'm at really low revs...

 

[bloke]

if the valves/seats are just on their way out then it can show up like a mis fire on tickover, plus the pops and bangs map will kill them anyway. losing fuel on compression stroke though exhaust valve can give you a weaker mixture, then run hotter burn and give pinking.

ecu can get 'confused' as it throws fuel in only for the lambda to show it as running weak etc...
leakdown test is easy enough to do, would be worth it if you can get one done.

 

[Benjiman46]

How would I check for faulty fuel injectors? Can I replace one or do you have to replace them all?

 

[bloke]

a faulty injector should give a flashing eml and show up on code reader, even the most basic ones should give a cylinder misfire number.

but they can be clogged of the pulse time can be off among other things. first check is resistance, should be 15 ohms. visual check they are spraying doesn't tell you much unless you've got one that's almost completely blocked. next is scope to check pulse time, i've got a power probe that's fantastic for checking injectors.

 

[Benjiman46]

Right, okay... well there's nothing showing on my RST box apart from the codes I've already posted. So I'm going to get a pair of new Lamda sensors because there's obviously a problem there, and take it from there I guess :/ I don't think it's valve seats, because it idles perfect and there's no smoke. Plus it only misfires intermittently at low loads. I reckon it's a mixture of dead Lamda sensors and a shagged injector or two. Pops and bangs remap is definitely being deleted... Grown out of it now anyway lol Cheers for your help though Bloke.

 

[Benjiman46]

a faulty injector should give a flashing eml and show up on code reader, even the most basic ones should give a cylinder misfire number.

but they can be clogged of the pulse time can be off among other things. first check is resistance, should be 15 ohms. visual check they are spraying doesn't tell you much unless you've got one that's almost completely blocked. next is scope to check pulse time, i've got a power probe that's fantastic for checking injectors.

Oh and my EML is constantly on... :/

 

[bloke]

flashing or on solid? assume solid, the lambda would explain that.

 

[Benjiman46]

flashing or on solid? assume solid, the lambda would explain that.

Solid mate, I've swapped front to back but no change which I find weird... I thought there might be at least SOME change but there isn't which to me would rule out O2 sensor... Correct me if I'm wrong though lol

 

[bloke]

de catted?

 

[Benjiman46]

Yeah it is

 

[bloke]

map could of killed the two of them. get it on live data and see what readings you get from the front lambda when it's upto temp.

 

[Benjiman46]

It WAS the Lambda sensors!!! I changed both and instantly the fault codes cleared, put the 98 RON map back on it (no pops and bangs) and it drives like a dream! Thanks for all the help!

 

[Namod182]

It WAS the Lambda sensors!!! I changed both and instantly the fault codes cleared, put the 98 RON map back on it (no pops and bangs) and it drives like a dream! Thanks for all the help!

Hi mate, sorry to jump in but where did you get them and how much were they? Same issue with mine. Just another thing to tick off the to do list

 

[Benjiman46]

I got them from Worksop Motor Spares and they cost £150 for the pair. You can get them cheaper than that, just don't be tempted by "universal" ones (even Bosch universal ones) Get NTK. They're normally between £60 and £70 each. They are both the same part number for front and rear with NGK/NTK. Hope this helps.

 

[Namod182]

I got them from Worksop Motor Spares and they cost £150 for the pair. You can get them cheaper than that, just don't be tempted by "universal" ones (even Bosch universal ones) Get NTK. They're normally between £60 and £70 each. They are both the same part number for front and rear with NGK/NTK. Hope this helps.

Cheers for the info, much appreciated :up:

 

[MicKPM]

The NTK/NGK are brilliant but if you're patient, you can get the OE Bosch unit on eBay for around £50.

Euros sell the Bosch for around £70 IIRC to

 

[pete_rawli]

@George@RTR_Parts sells the genuine Bosch ones for £59 posted