Lumpy idle & rich running.

[TBear]

Good afternoon all,
First time poster.
I have recently bought a 2004 Clio 182, which has a lumpy idle, and it's obviously running very rich.

It pulls well and hard; and it doesn't cut out; on tick over it sounds like it just has some aggressive cams; there isn't black smoke (suggesting serious overfueling) but I can smell fuel on idle when warm.

The car has a decat and a full Miltek system.

When starting cold; the EML flashes and goes out the second you drive away.

I haven't got my diagnostic machine at the moment to bring up that fault; but with the other symptoms; I'm thinking an o2 or maf sensor fault?

The reason for the post is before I go buying sensors left, right and centre, I was wondering if anyone else had had something similar; and what order is the most likely?

Many thanks for any help in advance.

 

[LeeRS]

Will be the lambda sensor.
Running a decat will make it smell of fuel and the lumpy idle is just a character of the 1*2. Some do, some dont.

 

[da rok]

as above, could be a lambda, could also be an air leak on the manifold causing lumpy idle or and exhaust leak confusing the lambdas, to rule out an air leak take some starting spray and spray around the intake manifold gaskets and any vacuum pipe connectors, map/maf/intake temp sensors... if there is a change in idle you have a leak... unfortunately you just have to listen for exhaust leaks...

 

[TBear]

Thanks for your help.

I've bought a new CTS and lambda (probably won't hurt)

It started running on three cylinders earlier; EML flashed, so I shut the car off and turned it back on; and it was fine.

 

[da rok]

hmm, running on 3 cylinders would point to a bad injector or coil pack

 

[bloke]

flashing eml is an injector.

 

[Mat Jones]

Eml will come on for a number of faults this doesn't point to an injector..... As above said it could be coil pack, injector, or plugs. Needs to be diagnosed properly, these Renault petrol engines are always a little lumpy. It's recommended that the sport models were run in higher octane fuel also.

 

[bloke]

Eml will come on for a number of faults this doesn't point to an injector..... As above said it could be coil pack, injector, or plugs. Needs to be diagnosed properly, these Renault petrol engines are always a little lumpy. It's recommended that the sport models were run in higher octane fuel also.

FLASHING eml.

 

[TBear]

All; thanks for your help so far.
I've not had much of a chance to do anything with the car yet; however it is now running on 3 cylinders full stop.

I've got a fault code reader this evening to check it over; it might sound like a silly question; but is it likely to point me to the right thing? As on previous cars (not renaults) it's given me a bit of a duff steer as to what the actual problem is.

 

[TBear]

So it appears to be cylinder 4; and random misfire.

I've changed to coil pack and no change; so plugs next, hopefully it isn't the injectors.

 

[TBear]

If it is the injector; can you replace just the one; or is it advisable to change all four?

 

[R3k1355]

They're only 25 euro each, you might as well do all four.
It sounds like injectors tbh.

 

[172PSD205]

My 172 had lumpy idle and it was 1 of the injectors, check the resistance of them with a multimeter, I just replaced the faulty 1 and the car has been fine

 

[TBear]

Thanks all a new injector rail and injectors sorted it.