tracking the cause of a mis fire

[jackb_ms]

Hello all

 

After passing it's MOT, my 21 has developped a mis-fire it only happen underload and often below 2000RPM

The engine is a EU2 VVC on roller barrels and Emerald

 

It seems I'm loosing all power for a brief moment (RPM drop suddenly) then everything is ok.

 

I've noticed a slight crack in the cam position sensor which will be changed but i doubt it will cure it.

 

I'm going to check the obvious, earth issue, battery condition, ECU connection, TPS at the weekend.

 

Anything else I should check?

 

Cheers

 

Jack

[Klunk]

Hi Jack ,

 

Does the EU2 VVC have a rotor arm and dizzy like an EU2 non VVC?

 

If it does, I had this problem recently with a friend's SLR on RBTBs. Couldn't find the problem so spoke to a mechanic friend and he said the K series are notorious for the rotor arm failing and allowing the spark to track down the camshaft. This appears at about 2000rpm under load.

 

Have to say I was sceptical (the one I removed looked fine) but I changed it and the dizzy cap for good measure. Completely resolved the situation. They're 'cheap as chips' so I'd start with this.

 

Of course, if it doesn't have a rotor arm/dizzy all the above is rubbish! 😬

 

 

Regards,

 

Giles

 

Edited by - Klunk on 5 Jul 2013 09:17:18

[jackb_ms]

Hi Giles

 

Thank you for your posting

 

I think I may have found the source of this misfire.

It seems its related to the throttle pedal position therefore the TPS.

Oily is sending one to me so hopefully that will cure it

 

The engine is a VVC so I don't have a dizzy. It's a version on the VVC-R 😬 which is a rare beast.

 

Jack

[Klunk]

Have just found a picture of the coilpacks - no wonder I couldn't find a picture of the rotor arm 😬

 

Glad you're sorted .

 

Regards,

Giles