I recently swapped from IK24's to NKG copper plugs BKR7E gapped at .035" for a supercharged application. Now the car is experiencing some strange issues.

-- Exhaust periodically pulses on idle.
-- Taking off from a stop in 1st gear at 1500-2500rpm exhaust sputters/pulses, there is a loss in power but once i'm about 3000rpm and the car is moving everything seems fine
-- car operates normally in other gears and past 3000 in first.

I thought my plug gap was too large so I regapped them at .033" I've also swapped out the MAP sensor with the new one and filled up with a fresh tank of gas. issues persisted.

Are these symptoms of a bad spark plug? Or could it be something else (injectors, coils, valves?) I haven't had a chance to swap the IK24 plugs back in.

 

hope somebody chimes in... I'm getting a pulsing exhaust as well...



D.

 

So am I...

 

if its not the plugs, than u could have a few bent valves.

 

Alan, the BKR7E is the same heat range as stock. I'd suggest a colder plug like the R5672A-8 (7173 NGK copper racing plug), or the IFR8H-11 (5068 NGK Iridium). Both are one step colder than stock, which is good for FI. That may have something to do with the issues you're having.

 

BTW, I wrote a novel about this a couple months ago https://www.s2ki.com/forums/index.php?showt...0&#entry9655960

 

I doubt it is bent valves since I've only recently taken it out of storage and been grannying it around a couple of weeks.

This weekend I'm going to go put back to the IK24 that were in their before. I've actually had the supercharge on for a year with the stock plugs before switching to the IK24's, it ran fine at stock heat range.

Doing some research I noticed that WLaurent had the same problems last month. He seemed to have cleared it with a valve adjustment.

https://www.s2ki.com/forums/index.ph...ic=478799&st=0

 

Just so I don't leave this thread dangling. I swapped in 4 new plugs and the car seems to be running well now! Looks like I got a bad plug from NKG.

For 2 bucks a pop, I didn't bother trying to figure out which one it was so I tossed all 4 out. Sleeping sounder now that the car is happy.