Spark plug fouling

[twobjshelbys]

Originally Posted by jhv48

Those plugs appear to be covered with fluffy carbon deposits and if so, that’s a rich condition. I wouldn’t run the car too much until you figure out why the injection system is dumping too much fuel into the cylinders.
It’s a good thing the car won’t start now. You don’t want to drive it much running rich, as the excess fuel can wash down the cylinders and cause real problems.

I concur. Mine looked like this.

However, I also had another symptom: My rich portion of the DFI tables were beyond 1/2 to 3/4 throttle. Running steady at that speed/rpm/position and then letting off the throttle would result in backfires... I could also get it to backfire by "foot on the pedal" acceleration/shifting like you'd get when merging into highway traffic and then letting off the throttle...

Do you have a backfiring problem?