Punto 1.2 16v sporting owner with problem

[steviedon]

Hi all,
Im new here and like to say hello!

I have a 02 plate punto the engine light came on so I took it to the garage where at the cost of £50 they put it on there machine and told me its the lambda sensor, so on the way home the light went out and stayed off for afew days then came back on then went off this happened afew times but the car was running fine no problems.

At the weekend went and started her up and she was missing alot on idle and when accelerator pushed small death spot and strong smell of fuel.
So I removed the sensor to give it aclean the color on removal was light brown which I think is normal but anyway gave it aclean put everything back together, started the car light was still on but car was running fine.
Took it out for a road test, was driving and acceleration was fine, stopped turned it of and 5mins later started her up and the missing and lumpy idle was back.
So got anew lambda sensor removed the old one and it was black so fitted the new one. Removed and clean all spark plugs which were really black to.

Put everything back to gether started the car and light still on idle is still alittle lumpy and still got the small death spot on acceleration smell of fuel and alot of black muk out the exhaust.

Ive phoned the garage and they said bring it in and they will put it back on their machine but at the cost of another £50.

So im asking everyone out there have you got any ideas
or know what the problem is?

cheers guys

 

[Ffoxy]

Hi & Welcome to The Fiat Forum, plenty of Punto experts on here, sadly I'm not one of them, however, until they show up, take a very close look around all the rubber pipes, every single one of them, that ventilate the engine breather system, a split or holed pipe can mess around badly with the engine fuelling, as can a blocked or collapsed hose. The best way to do all the above is identify them, remove them, inspect & replace if / where necessary, any that are in good nick clean them before replacement.

At the very least that will eliminate a simple cause before getting heavily into the technical stuff.

 

[jip0]

there are two lambada sensors did the diagnostics say which one?

if you did replace the right one the code still needs to be cleared afterwards

also there could be something else which is disturbing the lambada sensor and causing it to throw up an error

and finally if you want a cheaper option for diagnostics that you can use again and again then look in the punto guides section

there is a guide that will show you how to connect your laptop to the car and run a free programme that will allow you to read and clear codes and also a ton of other stuff

someone else will be along thats alot more knowledgeable then me and can give you more help

 

[steviedon]

Hi
Thanks for you post.
They told me it was the top sensor which i have replaced.
even if the sensor was faulty why is it running rich?
Thought these sensors sort out the air/fuel mix

 

[Ffoxy]

Hi
Thanks for you post.
They told me it was the top sensor which i have replaced.
even if the sensor was faulty why is it running rich?
Thought these sensors sort out the air/fuel mix

** see Post 2, a sensor can only do so much within the scope of its operating range / spec.

Did you fit a genuine sensor or aftermarket?

 

[steviedon]

was a aftermarket sensor.

 

[Ffoxy]

Might explain at least a part of it, Fiats are sensitive to the sensor make. Getting the correct item can turn out cheaper in terms of trouble even if they are a bit more expensive. I'd still suggest you closely examine all the pipes in the breather system. If you dont know why, a split or hole in those can easily upset the air / fuel mixture ratio's, making it lean so the sensors richen it up as much as they can causing poor running...

 

[Stz1984]

Hi
I had that prom when I have a mk2 sporting, I cleaned both sensors in petrol and in end got some from abreaking punto and proble was fine. mine wasn't running lumpy though.

 

[steviedon]

checked today no splits or blockages in any air pipes but did find a crack in the exhaust manifold?
cleaned both sensors again today started her up seemed to be running fine light is still on coughs eveny now and then and still black muk coming out the exhaust.
Could the manifold be causing this problem?

 

[Ffoxy]

Not being an expert I couldnt say for sure, but it could be reducing the exhaust back pressure & the gasses the Lambda sensors are reading I'd have thought.

 

[steviedon]

Yet Thought you would say that, they cant be welded the Catalytic Converter

is part of the manifold had a quote for £380 more than what the cars worth :0

So if you know of anyone selling one cheap please send me a pm manky thanks for your help, also done a double check on the breather pipes and found the engine breath from the rocker box has 2 splits in it.

 

[Ffoxy]

Try a Wanted Advert on here maybe? Then a breakers yard?

Change that breather pipe though, my daughters 1.4 Ibiza suffered chronic problems with a split pipe... ran fine with a replacement fitted.

 

[steviedon]

Took off the old cat today found 3 cracks in it so could say its had it.

Looks like I have found 1 for £80 used only done 18000miles so fingers crossed.
cheers for your help guys and will let you know if it cures the problems