I always run it. I did a B18C swap to my CR-X, was bummed out cause it wouldn't start... hmmmmm. what could it be.... So I took a last look at my engine bay to make sure everything was hooked up... Seemed all fine, then I noticed I didn't have that valve cover ground to the chassis..... figured I might as well put it on.. I did, and gave the motor one last try to crank up... IT DID!!!! And yes, I had all my other engine/transmission grounds hooked up.