RobEvo5

Just changed my spark plug oil seals due to them letting oil past badly, and having read a few threads decided to put some in copper NGKBKR7E plugs and just change them frequently.

However upon putting the car back together , I started the car and let it idle until the fan kicked in to just warm the car up and all was well and puring fine. But soon after then turned off ignition, then started up and went for a drive. But the car is now missfiring badly and running like a bag of shit.

Its not the coil packs as I have a spare set and tried that. Therefore now wondering:

a. if there is a possibility i've been unlucky and bought some dodgy plugs.
b. what else might cause the car to missfire, other than coil packs and plugs
c. If using copper BKR7E's are not the right plug for a OEM car.
d. I might have disturbed the magnetic pickup on the rocker cover, if these fail, could this cause a missfire.

Its really bugging me

Cheers

mattxx

Rob, sorry to hear that. Don't know if I'll be of much help but I use the same exact "NGK Copper Racing plugs" on my supercharged S. One thing I made sure of was to research what gap to use if I was boosted. There is no definitive answer as I discovered but most people were using the same gap or similar and had no problems. I have no problems.

Did you properly gap them with a wire gap tool before install? OEM gap would wider to prevent fouling and to encourage a cleaner spark. Boosted gap would be the opposite, a tighter gap to prevent spark blow out. I would research what gap people use on the copper plugs for OEM car because it might not be the same spec as OEM plug.

Croc

i just put what wner manual suggests - NGK PFR7G-11S and it worked OK.

RobEvo5

I checked gaps and they came pre gaped at about 0.040" but you might be right the gap might need to be closed up but struggling to find any info. It only seems to be you FI guys running coppers..

For the sake of £40 I'm going to buy some OEM platinums, and see how that goes. Will report back either way.