I just figured something out today. When my engine is cold and hasn't warmed up yet, it runs very smooth and feels like there is more power. Once it warms up, it knocks slightly and has trouble accelerating. I'm not sure where to start looking for the cause. I'm running 89 octane gas in hopes of curing the knock which I thought i had all the time. I recently replaced my EGR valve and never noticed a difference between it and the old one. I replaced because I thought it was sticking, but it really wasn't.

I have a '90 305 TBI.