Clio Missfire 1.2 16v

[deadonkey]

Hi all.

Ive got a missfire on the clio.
Driving home last night it missfired from cold a little bit and them went into safe or restricted performance mode. With the little engine light flashing on the right hand side of the dash lights.

Called the RAC out. He cleaned the leads with GT85, changed the spark plugs and cleared the faults with his little computer thingy. He then checked the compression on each cylinder and said it was good and all the readings were the same. He checked the spark plugs on an individual basis and said that they were ok.
Anyway it still missfires.

Ive had the same problem around 20k miles ago but took it to a garage and the changed the plugs and all was well. Not this time tho.

I need it fixed quick because ive just traded it in.

Any ideas on what it might be?
Coil Pack

 

[Fred@BTM]

coilpack, tdc sensor

 

[Djw John]

yeah coilpack first then if that doesnt work the tdc sensor usually does!

 

[mattjk]

Can you wire brush tdc sensors?? or clean them with a stiff brush n solvent or something

 

[Fred@BTM]

just buy a new one

 

[mattjk]

They aint cheap though lol i was just curious

 

[deadonkey]

Since Ive traded the car in I contacted the place where I sold it to.

They rekon its the ECU and its gonna cost a load to fix but if I give them £350 they will take the car off my hands as it is.
I dont know how they know what it is since they havnt looked at it.

I suspect the coil pack, I will contact a renault dealer tomorrow, and get it fixed myself. I doubt its much

 

[edde]

Coil pack most liky but there laods of potentials could be a coolent temp.

 

[A18XHO]

its about £45 iirc, they always say its the ecu or it needs a new throttle body. Put a new coil pack on it and it should fix it. Just remember what way round the leads go and you should be fine.

 

[ditz]

its about £45 iirc, they always say its the ecu or it needs a new throttle body. Put a new coil pack on it and it should fix it. Just remember what way round the leads go and you should be fine.

this is the only thing i dont like about this site, nobody can say what the problem with a car is over the internet, they can tell you the possibles but it dosnt accheive anything..
so you have a miss fire, things that could cause an engine to missfire could be....
spark plugs
ht leads
coilpack
injectors
compression issue
coolant temp sensor
crank sensor
map sensor
ecu
wiring between any of said components and the ecu
dodgey earths/connections etc.

in my oppinion, take all the suggestions people have offered you on board, but before you do anything do some diagnostic work yourself ie run the engine and pull each plug lead off in turn to see what cylinder isnt firing.
if you a cylinder or multiple cylinders not firing, put an old spark plug in that lead and see if you get a spark out of it.
if you dont or its very weak.. give the wire leading to the coil pack a quick check and if thats ok the problem is the coil pack

 

[TomTom]

Er to be fair the 1.2s ECUs fill up with water causing corrosion eventually and it slowly eats away at the wiring loom. If it is that it'll usually come up with the Pedal Potentiometer Track 1/2 fault. If you've tried plugs, leads, a coil pack I'd put money on it being either the computer full of corrosion, or the block plugs going into the computer corroding. If your lucky you'll get away with a good clean, blast off with compressed air, WD40, blast off again and try it.

If its silicone in the wiring loom block plugs it'll throw up the Programming Throttle Limits fault and put the car in limp mode.

It won't be the TDC sensor.

They rekon its the ECU and its gonna cost a load to fix but if I give them £350 they will take the car off my hands as it is.
I dont know how they know what it is since they havnt looked at it.

I suspect the coil pack, I will contact a renault dealer tomorrow, and get it fixed myself. I doubt its much

its about £45 iirc, they always say its the ecu or it needs a new throttle body. Put a new coil pack on it and it should fix it. Just remember what way round the leads go and you should be fine.

Because the faults common as anything.

 

[deadonkey]

The fault code on the RAC blokes computer was

"Missfire Cylinder 2"

"Missfire Cylinder 3"

I was looking over his shoulder when he downloaded the faults

 

[ditz]

The fault code on the RAC blokes computer was

"Missfire Cylinder 2"

"Missfire Cylinder 3"

I was looking over his shoulder when he downloaded the faults

i would say its more than likely to be the coilpack then, but the incompitent rac monkey should have detected this-- its the first thing you check when faced with any missfire wether or not you actually have a spark on all cylinders.

 

[deadonkey]

he took all 4 spark plugs out and earthed them on an engine mount, then he told me to turn the engine over. He said that all 4 plugs worked fine.

He then connected his computer, downloaded and cleared the above faults.
Then he put it in live mode or something and he drove the car around abit I had the laptop on my lap it said no faults detected and even though it missfired it didnt register on his laptop.

It seemed to missfire more when he was in the wrong gear, say in 3rd or 4th going 20mph.
It seemed ok when it was revved.

 

[TomTom]

he took all 4 spark plugs out and earthed them on an engine mount, then he told me to turn the engine over. He said that all 4 plugs worked fine.

He then connected his computer, downloaded and cleared the above faults.
Then he put it in live mode or something and he drove the car around abit I had the laptop on my lap it said no faults detected and even though it missfired it didnt register on his laptop.

It seemed to missfire more when he was in the wrong gear, say in 3rd or 4th going 20mph.
It seemed ok when it was revved.

Injector would do that, no faults as its basically just an earth and 12v feed. They're cheap but the annoying this is they never put a light on/code on the computer so its a tad harder to diagnose.

 

[ditz]

he took all 4 spark plugs out and earthed them on an engine mount, then he told me to turn the engine over. He said that all 4 plugs worked fine.

He then connected his computer, downloaded and cleared the above faults.
Then he put it in live mode or something and he drove the car around abit I had the laptop on my lap it said no faults detected and even though it missfired it didnt register on his laptop.

It seemed to missfire more when he was in the wrong gear, say in 3rd or 4th going 20mph.
It seemed ok when it was revved.

Injector would do that, no faults as its basically just an earth and 12v feed. They're cheap but the annoying this is they never put a light on/code on the computer so its a tad harder to diagnose.

*sometimes* you can pick up a discrepency with an injecter with a screwdriver.. put a screwdriver to each injecter and put your ear to it.. and obviously you are looking a uniform sound but you want a crisp click from each one

 

[Olly1.216v]

mine was misfiring took it to renault as its under warrenty mechanics went out with laptop. Was defantly misfiring so they changed coil and now it seems fine since