[Steve_G]

Hey all, my 197 has over the last couple of days just started flashing the orange engine management light for approx 30 seconds. Long story short, this time last year, it did the same and flagged up cylinder 1 misfire on renault diagnostic machine. Swapped spark plug and coil to cylinder 2 and 3 and erased fault code, few days later EML started flashing again, plugged in again to find cylinder 1 misfire so assumed must be the injector at fault and had it replaced under warranty. Now 9 months on EML started flashing again with cylinder 1 misfire. Just wanted to know if there were any widely known problems with this as I am going to to do the swap plug and coil over again and see if its still isolated to cylinder 1, if it is then injector can be done again free under parts warranty. Oh and it had the injection computer reprogramme done to when fault first occured last year.

Any help would be great

 

[madnoel10]

Instead of changing the coils and plugs around why not try disconecting each injector in turn. Whichever one has the least effect is usually the misfiring cylinder.

Also remember number one cylinder on Renaults is the one closest to the flywheel. Plus as the coils are wired in pairs when one goes faulty its partner is also lilkely to be affected.

 

[Steve_G]

Thing is though, when the EML does start flashing it produces no effect to the drive of the car and idles perfectly fine so I dont think I would see much from disconnecting each injector at turn and from previous experience it isnt a good idea to disconnect injectors while vehicle is running....

 

[madnoel10]

.......from previous experience it isnt a good idea to disconnect injectors while vehicle is running....

It does less harm than either a poor ignition coil or duff spark plug.

 

[Recycled Scenic]

disconecting each injector in turn. Whichever one has the least effect is usually the misfiring cylinder.

:iagree: this is usually the most effective way to identify a faulty cylinder on these 16 valve Renault engines as the coils are wired in pairs so you can't just disconnect one.

I changed a 2.0 F4R in a Scenic last week and had a problem with a misfire on No3 cylinder. The plug was wet through. I changed the plug and pencil coil which didn’t resolve the problem. So thinking the problem was a faulty injector I swapped the complete fuel rail from another 2.0 Scenic I have and the misfire was still there!

I then connected a spare pencil coil and spark plug to No3 coil connector and earthed the spark plug to the engine and there was clearly a good strong spark.

My mate then noticed one of the wires feeding No3 injector had a kink in it and investigating further we could see that the wire insulation was damaged and the copper wire inside was broken and all green with corrosion when we stripped the insulation back. We soldered the wire back together and used shrink tube to re-insulate the wire and the misfire was cured.

It looks to me that the wire must have been trapped at some point by the aluminium housing that protects the fuel rail.