Trying to track down why the motor has a stutter if I get into boost. It was time to check on the BR7EF plugs anyway. Pulled the bank 2 plugs tonight. Bank 1 will have to wait til Friday. Plugs have about 200 miles on them - first 100 with race gas, last 100 with E10 94. They have seen little boost. They are not sooted up like the 9's were from driving around town, but do have some deposits on them. Did have some wonky issues that were fixed by swapping out the Roadrunner for the factory PCM. But it didn't help the stutter.

 

Where these pulled right after a WOT pass then shut down? If not they will not tell you much of anything. Also need to cut the threads off so we can see the fuel ring at the base.

 

Ya, not a drag run plug reading situation. Just noticing the difference in colouration on the insulators with #2(far right) being much lighter and #4 also lighter than 6 & 8. Also, could the yellow deposits on the ground straps be from having leaded race fuel in the tank for about 100 miles of mostly low load operation?

 

Bank 1 were all different as well. But the Road runner PCM was doing strange things with the injectors - like periodic dips in INJCD on one bank or the other, but not both at the same time, while under steady state conditions running OLSD- so who knows what else was going on if the driver circuits were screwed up.

 

There is an awful lot of "speckles" on those plugs. Besides that with any amount of drive time it's useless to look at them.

 

brown speckles can be a sign of detonation.

 

How about non-baffled valve covers and a full catch can?