Misfire/holding back

[T3gav]

Hi guys, my 182 has started holding back/misfiring especially when cold, I put it on a scanner which found the air temp sensor to be playing up so I changed it which made the car much better but it is still there. No other codes came up, does it sound like a coilpack issue? I'm guessing it doesn't need the ecu resetting after changing sensors etc?

 

[N4TH4N]

Doesn't the code need to be cleared?

 

[T3gav]

Good point, I'll try that first! The garage did say it would refresh with the ignition switched off and back on though and it did get a lot better so assumed it had worked.

 

[warwickstingray]

Unbolt coilpack and check the bottom. They can crack and rot inside.

 

[T3gav]

Hmm so checked the code and it had gone, checked and replaced the coilpack (even though it looked mint) and still got the same problem. Is much worse when cold, leads/plugs you think? Any other ideas, no codes other than brake pedal/traction control occasionally, but that has always come and gone and the car still does it with the traction control off.

 

[T3gav]

Someone has suggested could be fuel filter issue (blocked) car has only done 85k, is it usual for the filters to get clogged up? I see the service interval is 150k, how hard is it to get to the filter to check? Thanks

 

[Wilky0302]

Could be the pre cat lambda sensor as i think it uses that until the temp of the engine is normal it then uses the post cat sensor

 

[T3gav]

Cheers bud will try that

 

[T3gav]

.

 

[T3gav]

Could be the pre cat lambda sensor as i think it uses that until the temp of the engine is normal it then uses the post cat sensor

Changed the pre cat lambda and it made the car 1000 times better, thanks! :smile: still got a hesitation though occasionally, am thinking injectors? No codes and I've replaced most other things. Most of my journeys are very short, maybe it needs a decoke!

 

[Greeny.]

My old 172 had very similar issues, ignored it for a while as it only happened once in a blue moon but eventually it gave up running on 4, ended up being an injector.

 

[LeeRS]

you can see if there has been an injector fault by doing the dash diagnostic I believe.
I think they are resembled as the letter T iirc.

hold in stalk button (the one to flick through mpg etc) and turn ignition on.
the dials will start moving and you can flick through the codes with the stalk button.

just in cas you didn't know

 

[T3gav]

Cheers bud will try this later, I didn't know!

 

[MicKPM]

The T is for injector pulse information which the clockset uses to work out fuel consumption. It doesn't mean there's an actual Injector fault.

 

[LeeRS]

Ah, there you go. Guru has spoken

 

[T3gav]

I got no error codes showing doing that dash thing just a fuel symbol saying 38 gallons I think.

 

[Diagro]

I got no error codes showing doing that dash thing just a fuel symbol saying 38 gallons I think.

38 GALLONS?! is your entire car the fuel tank?

 

[T3gav]

Lol, I fail! 38L I meant. So on the way to work this morning the car just cut out completely, no warning just died, no power steering lights etc, started up again with a bit of hesitation and drove normally, wtf!

 

[trenace188]

Cranksensor ? Bad earth ?

 

[MicKPM]

Honestly, you really want this on something that can churn out reliable live data and someone who knows what they're looking at driving it. ODBII is rubbish and you are unlikely to get reliable code information using it.

Assuming that the issue vanishes when the car is up to temp, I'd guess at it being CTS or H02S related.

 

[T3gav]

CTS? The lambda sensor solved the terrible misfire when cold, this seems to be all the time and is only slight but I know it's there. When it cut out this morning it was warm. Someone suggested the cat could be blocked, bit of a long shot...

 

[MicKPM]

Ceramic CATs rarely get blocked or collapse... It's kinda like an urban legend of car faults.

 

[flebay]

Ceramic CATs rarely get blocked or collapse... It's kinda like an urban legend of car faults.

The 182 came with a metal substrate catalytic converter so even less chance off being blocked or collapsed.

 

[T3gav]

Thanks guys, appreciate the responses

 

[T3gav]

Changed injectors, misfire still there, exactly 3300rpm under load in every gear. Someone suggested burnt valve, will change plugs and do a compression test tonight.

 

[flebay]

If the spark plugs or ht leads are the originals then that will be the problem, weak spark.

 

[T3gav]

HT leads I changed few weeks ago and spark plugs probably less than 10k ago, hoping it's just a faulty plug but it probably wont be that simple as I've yet to have a faulty NGK plug on any of my cars.

 

[flebay]

NGK will be fine there don't go wrong in that time. Are the ht leads genuine Renault as the ones from euro car parts are poor quality.

 

[T3gav]

They are Formula Power leads, very good quality. Changed the plugs last night, seems a little better, did a compression test too, 200 on every cylinder. Going to book it in for cambelt soon so will get them to have a look. Could it be a dephaser/vvt issue?