Mis-fire with BR7EF's and I am lost.
 

I recently installed a nitrous system and went to the BR7EF's. I now have a mis at idle and the car shakes. The code is coming up on cylinder 7. If you get on it or rev the engine the mis goes away. If I put a stock plug back in the cylinder it goes away. I even switched coil packs, spark plugs and the wires from a different cylinder and the mis stayed on number 7. I am lost and have no idea where to start trouble shooting now.

Make sure the plug does not have a crack in the porcelain. I had one plug cracked out of the box.

Yeah we switched plugs from #5 and #7 and the mis fire stayed on #7. So the plug is good.

thats werid whats the gap on the plugs?

Pretty cold plug and combined with cylinder that tends toward lean = misfire. You might try swapping injectors to see if that helps.

FWIW, I run that same plug in my Lightning at .035" for the added boost and it does idle rougher than the TR6's.

Bird

Ill have to double check what the plugs are at again. Im wondering about upgrading the coils to the truck coils and see if that might pull it out. Its fine whenever its under a load but as soon as an idle it starts missing. Im gonna do a compression check to make sure the cylinder is good and that im not getting any blow-by.

Could it also be that maybe that injector is dirty and its not got enough fuel pressure behind it at an idle. Then once the engine goes under load and fuel is increased injector can spray and brings the cylinder back?

Well did a compression test and the results were very dissapointing. 130 accross the board with the exception being in cylinder 7 which very low at 80. So I guess im in for a rebuild.

That sucks dude. I wonder if the piston or ring land came apart.

I dunno damn thing only had 80k on it and 25k of that were interstate miles. I didnt even get to spray it yet.

Time to build a 6.0