IN an earlier post, i mentioned that i was having injector troubles however, ive noticed that when i have my car parked and rev the motor a few times, i get this black oily like crap that comes out of the exhaust.. What is this and what is causing it? The fuel pressure is set to 37 psi.. i check the ignition timing the best i could and it seems to be pretty close... could like 1 or 2 degrees off cause this? Thanx for any info..