VN Misfiring

[LMac]

Hi,

My 5-speed 3.8L VN has been misfiring the last few weeks, particularly when going uphill or when giving it a bit of stick. The car can be driven softly to avoid the problem most of the time put this is not an ideal solution. The car has relatively new spark plugs and leads, so I think it may be an ignition coil problem. Any ideas/advice would be greatly appreciated.

Cheers,
Luke

[mouce]

I reckon you'd be right in what you think. Sounds a lot like a coil pack problem. An easy way to 'test' (although not completely accurate), is to go for a bit of a drive, then see how warm each of the coil pack modules gets. If one is a lot hotter than the rest, it's normally a good indication that it's buggered.

Is it a series 1 or series 2 VN? If it's a series 1 it would be a good chance to upgrade to a series 2 coil pack setup, just a bit more spark.

[beefcream]

ive had this twice now.. most likley ur coil or faulty dfi module
expensive bastards!

[AdamIan69]

i have had the same problem with my VN, i have replaced coil packs and DFI module, map sensor spark leads and i have reletive new plugs? i am starting to think it has somthing to with the Crank Angle sensor as it only misfires under load and when the engine is at operating temperature. Has anyone got any ideas?

[beefcream]

if its the crank angle sensor dont u put some cold water over it and see how it goes. if its better then theres your problem

[mouce]

If it's CAS, either it works or it doesn't. Yeah...dumping water on them cools them down so that they start working again, but I've never heard of a CAS leading to a misfire, only stalling.

That said...I could be wrong.

[AdamIan69]

i took my VN for a drive tonight waited till it got to full operating temperature, and then pored 2 litres of water over the Crank Angle Sensor, to cool it down. it didnt completly stop the miss, but helped it considerably. ( i cant imagin 2 litres would have made the CAS completly cold again though, give it a go and tell me how you go.