Missfire on Cylinder 4

[mattbrfc]

Plugged the car into a cheapo ebay diagnostics thingy. and its come up with a Cylinder 4 Missfire. Now i knew i had a Faulty Pencil Coil which i have now replaced (Replaced two as they were the original grey ones) Now the engine is running better than what it was, Now tried to clear the code but the fault is still there, Swapped the faulty Pencil coil to another cylinder and still showing up as cylinder 4.

Now which is cylinder 4 as im looking into the engine bay and what other causes other than pencil coil will cause the fault?

Thanks
Mat

 

[glowworm105]

Number 4 is the drivers side when looking into the engine i think someone may correct me , check for water in the plug holes i had a missfire which was caused by water sat in number 4 plug hole which ruined the spark plug aswell, a faulty injector can cause a misfire aswell

 

[mattbrfc]

Thanks for the reply, that was the Pencil Coil that was goosed and has been running rough since Friday Morning, yet even after a good few miles the OBD Light on the dash didnt flash up till Friday Night, Replaced the coil today, running a bit better, still very slightly shaky when idling (idles smooth tho) and the light wont go out. May take it for a spin and see if it clears.

Matt

 

[glowworm105]

Mines shaky on idle aswell and i remember reading something about the light will go out itself after a good couple of runs ,

 

[mattbrfc]

Ah right, I will keep and eye on it over the next few runs then.

Thanks
Matt

 

[172 chris]

number 4 is the 1 next to gearbox side

 

[glowworm105]

Its backwards on a renault iirc so number 1 is gearbox side but i could be wrong

 

[Xanda73]

When I read 'goosed' I looked to see where you were from. Knew it had to be around here...

 

[davemittell]

When clearing the fault codes are you doing it with the engine off or on?
Engine has to be off with ignition on to clear.
Check the wiring to the pencil coil this gives issues.
Also check carefully no.1 cylinder as 1 and 4 and 2 and 3 are generally linked so can throw you off.
No.4 is timing belt end, harks back to the old renault 4 days when the engines were put in longitudally with the gearbox at the front. meaning no.1 was closest to the front of the engine which was the gearbox end!