Miss fire - where to start?

[bing_17]

Ok, i know the RS' dont tick over too well but this is definatly a miss. its on tick over and upto about 2.5-3k when reving slowly. (Clutch in, parked up)

Ive changed the plus as they were ready anyway but now i need to know what to look at next, as i dont want to go and buy a part i dont really need and im guessing the coils are pretty pricey.

Can anyone help?

Thanks in advance

 

[ditz]

right you've changed the plugs,,
next you need to let it tickover, and see if each coil in the coilpack is firing by pulling each lead off of the coil pack one at a time and visually checking for spark and listening for change in engine note
you may want to use some insulated pliers if you are a girl......

chances are it will be dead on 1 cyl as they are notorious for coil packs, if it is dead on 1 then yep coil pack.

if you get a good spark out of each it can be a bit more tricky to diagnose, can only be leads or compression then assuming the plugs are ok (and assumption can be moter of all f**k ups)

let me know how you get on with that and i'll advise further

 

[Ross M]

what are the main signs of a failed coil pack ?

 

[SkidMarx]

^^ A missfire!

 

[ditz]

what are the main signs of a failed coil pack ?

lol just let us know the problem you have fella no point trying to guess from other peoples problems.



but yeah what he said.. a missfire!

 

[bing_17]

right you've changed the plugs,,
next you need to let it tickover, and see if each coil in the coilpack is firing by pulling each lead off of the coil pack one at a time and visually checking for spark and listening for change in engine note
you may want to use some insulated pliers if you are a girl......

chances are it will be dead on 1 cyl as they are notorious for coil packs, if it is dead on 1 then yep coil pack.

if you get a good spark out of each it can be a bit more tricky to diagnose, can only be leads or compression then assuming the plugs are ok (and assumption can be moter of all f**k ups)

let me know how you get on with that and i'll advise further

Luvly, that was my next port of call, and im glad you've just said that, ill give it a go tomorrow after work.
Ive heard something about the tdc causing a slight miss as well, is this right mate?

How much are coils by the way?

Thanks again

 

[ditz]

coil pack i last got from renault was i think off the top of my head 47 quid.
defiantely no more than 60 retail

never had a tdc sensor cause missfires like thats its normally starting problems/cutting out

 

[Beef-Mc]

Spark plugs, Ht leads, coil pack in that order, the 3 main causes of a misfire.

As above about the TDC sensor though.

 

[bing_17]

coil pack i last got from renault was i think off the top of my head 47 quid.
defiantely no more than 60 retail

never had a tdc sensor cause missfires like thats its normally starting problems/cutting out

Not 2 pricey then tbh,

Yeh well i had a tdc sensor go on my megane, obviously wouldnt start, but i just heard somewhere that they could cause a miss fire but wasnt sure.

anyway, ill check the coil tomorrow and then report back, keep your eye on this post m8ty!

 

[Ross M]

what are the main signs of a failed coil pack ?

lol just let us know the problem you have fella no point trying to guess from other peoples problems.



but yeah what he said.. a missfire!

i already have but noone gave me a direct or helpful answer.

 

[bing_17]

Right, i ran the engine, disconnected one lead at a time and the engine note dropped as expected, its got a brilliant spark on each one aswell, it will jump a inch and half, very strong.

So, now where do i start looking guys?

 

[ditz]

dropped on each as much as eachother? more than likely leads mate. bit of a crude method i use to see if leads are breaking down is run your hands over them and see if they shock you..

 

[The Chubby Pirate]

Exact same thing happened to me the other day, car was firing on 3 cylinders,car was seriously lacking in power so asked the old boy (mechanic) and he said it could be one of three things...

1. Coil pack
2. HT leads
3. Sparks

Changed the sparks and although the car was igniting fine the car was still very much lacking power...

Coil pack change and its rapid again, i was gonna change the leads for good measure but ill not bother as i have seemed to have cured the ill that was.

Also the engine management light came on, that required a diagnostic from a local garage at £30...

 

[bing_17]

Might buy a coil pack then, how much are leads guys?

 

[ditz]

if you are getting a strong equal spark out of each it wont be the coilpack mate.

leads are over a ton from renault but you can get magencor ones cheaper about 70 quid i think

 

[bing_17]

OOO fook the reno ones lol, i shal invest then i reckon

 

[R20 CWH]

arse, just clocked the prices for leads.

anyone got links to the cost of leads and coil pack?
Mines misfiring. JOBBY!

 

[Big Bob]

so its ok but when it should be on tick over its running at about 2-3k rpm

is that the problem just revving high at tick over ?