Misfiring + Engine Light

[The Fatty]

So with the leads swapped around it works all ok? i.e the misfire has gone?

 

[The Fatty]

it mean the problem is on the 3rd cylinder. What you need to do now is check if its the injector or coilpack/ht lead. To do this, remove the fuel rail as described above and sway injector 3 for injector 4. then put it back together and do the same unplugging the electrical connector test again. if the 'no effect' has moved to cylinder 4, then its the injector, else its the Coilpack/HT lead/spark plug. remember injector 1 is at the gearbox end and 4 is at the timing belt end.

that should have read injector 2 and injector 4 btw (i'm miss-read a previous post which said third from the left, not cylinder 3!), i'm sure you swapped the correct one anyway? its regardless now anyway as from what you have just posted, all injectors are working.

 

[jesus]

Yeah swapped them over and the problem has gone completely. I'm really confused now! Any ideas what could be the issue?

 

[The Fatty]

I would say the HT lead needs replacing then. Its probably damaged/broken down inside, and by moving it you have just made a better connection for it. it might last like that for a long time, or could fail again tomorrow. If it was the coil pack or spark plug, you would generally expect no change from just swapping a lead over.

 

[jesus]

I'll leave it until I can source some replacement ones or the misfire comes back. I need to get to work at 4am tomorrow morning so was panicing a bit!

Where are best for new leads, and are standard or uprated ones the best bet?

 

[The Fatty]

standard OEM ones are fine imo. hope its still working all ok for you tomorrow morning 4am is a mega early start!!

 

[jesus]

Yep - I don't usually do earlies and I've got 9 days in a row doing them starting tomorrow :dapprove: trust the Trophy to throw a hissy fit before it has to do a bit of work.

Are there any difference in standard or uprated ones? Are they even uprated? Or just a different colour? (I want some red ones ).

 

[The Fatty]

there might be a difference, but you wont notice it on the Clio imo. I will let someone else take over from here though as i'm not 100%

 

[jesus]

Sack it I'm going with OEM, I'm sick of spending money recently! Saying that though, would it be worth changing the spark plugs as well? I didn't actually check those but I don't know what I'd be checking for anyway.

Going off my service book they were last changed as 48k (29/1/09), it's now on 82k.

 

[The Fatty]

if they haven't every been changed since new and your car is 50K+ on the millage, then yes I would be changing them as well.

 

[jesus]

Might as well get it all done at once. Where is best for the parts, GSF/eurocarparts? I want OEM leads and NGK plugs but I know some places often use non-genuine parts.

 

[jenic]

Renault for leads and G172 for plugs

 

[The Fatty]

I always use GSF, they have the NGK plugs, but I cant see HT leads on there for some reason, so you may have to go else where. G172 on here is a good shout.

 

[MRBILLYUK]

Yeah swapped them over and the problem has gone completely. I'm really confused now! Any ideas what could be the issue?

Just been reading your post . You say the problem has gone now ? Maybe the problem was just a loose lead ? And with all the fiddling about you've now put the lead back on as it should be . Just a thought .

 

[jesus]

I checked that they were all securely in their places, however tomorrow or whenever I get the new leads I'll swap them back around and make sure they're in again and see if the problem comes back. Definitely out of the ordinary but the members in this thread have been a massive help.

A big thank you to everyone that helped out and suggested ideas, special thanks to The Fatty I owe you one mate :cheers:

 

[jinjur]

I would eyeball your sparks plugs for cracks or damage too bud as they come out.

I have seen cracks on plugs cause similar.....also check the plugs for signs of flashing (burns around the outside of the ceramic) as this may be a good pointer that moisture got in too.

Removing and replacing the plug leads could have dissipated problematic moisture as well. At least you have narrowed it to an ignition problem bud.

Best rule above, replace them all with OEM NGK ones......at that mileage it will be wanting them.

I have an intermittent misfire at the mo and i will be doing all of the excellent steps advised in here when it comes back.

​J

 

[jesus]

Cheers bud there's some really useful information in this thread. New NGKs are on their way and I'm trying to source some OEM HT leads as cheap as possible just for extra peace of mind. At least I know what's been changed then and when, the coil pack is less than a year old so it rules that out too.

 

[jinjur]

If you get a good deal on leads let me know bud as i could have to go down the same route

Cheers

​A

 

[jesus]

£54 was the best I could get, from Adam at Renault Wolverhampton. His number is in my other thread if you need it mate.

 

[jinjur]

Spot on bud, cheers

​J

 

[jesus]

Just noticed that my MPG has gone down by about 3-4 which is unusual as I've been feathering the gas today. I'll keep an eye on it but does anyone have any ideas as to why it might have gone down?

It could be just from when I had it sat at idle for a bit yesterday. It's not going up any higher than 30 though with gentle driving.

 

[The Fatty]

it will go down fast if you leave it idling and take ages to go back up again I find.

 

[Xanda73]

Jesus - did you get the new leads fitted and/or did the misfire reoccur? Were you thinking the reduction in MPG was connected? I ask because I have somewhat similar symptoms, and I hate it when people don't close their threads!

 

[jesus]

Fitted the new leads and it had already gone away but it hasn't come back since. No idea about the mpg, I can't remember what it was 'before' so couldn't tell you! It's low 30s now though.