Hi guys.

After following all the procedures of installing new NGK Iridiums (the right ones) my engine is running very rough.

I replaced with the stock plugs and the engine still is very rough.

I have checked each plug inside the block and each one is sparking.

I believe the problem lies within the electronics somewhere, but the connections were made exactly the same and have tested other locations.

Could someone tell me if I may have ****ed the ECU during this install or perhaps if there is another solution? Thanks.

 

did you try to gap it? or did you check the gap?

 

did you cross the coils wires during the reinstall? Did you gap the plugs? Which plugs are these EXACTLY?

CJ

 

was the engine running this way before the install? If not, has to be something with the install. like iTune said above check your coil wires too see if they were crossed.

 

Iridium Option BPR8EIX (NGK) I checked the gaps at 0.7mm and did not cross the coils at all. Going to reset the ECU now and see if it can sort itself out..

A stationary Evo VIII makes a very pretty albeit expensive paper weight!

 

well in the ngk iridiums, the stock heat range would be 7, so you're one step colder. i don't know about mm, but i always gap mine to .026". and i have regular bolt-ons and didn't see any more knock on the dyno running 7 plugs than i would of running 8's.

 

.027in (.7mm for you metricheads) is correct.
Check the porcelain for cracks or defects. If all else, take one of the old plugs and test 1 by 1 with the new sparks. If the roughness stops then you have figured out which plug it is. Just some suggestions, good luck!