Originally Posted by wolf cosworth

Good afternoon ,

confused here.

Had a saphire 4x4 MSD close loop stage 2 this car ran a lot better on irridium IK27 idle , ... then with normal plugs AGR 12PP.

So when I bought my 3dr last month thought put also IK27 in there but the car is for some reason above 4000 RPM running worse and misfiring.

And yes new rotor / cap and leads from MSD installed.

I did not touch the plug gap still at 0,75mm I believe .

Any ideas ?

gr,Steven