Amazon.com: Ferrari Maserati of Washington BG Dynamic Engine Restoration Service kit : Automotive
Buy Ferrari Maserati of Washington BG Dynamic Engine Restoration Service kit: Engine Cleaners & Degreasers - Amazon.com ✓ FREE DELIVERY possible on eligible purchaseswww.amazon.com
The BG dynamic engine restoration service may be worth a shot.
Also this video demonstrating how well EPR works on a similar situation as OP.