One area that is often overlooked during a service on this engine is the fuel pre-filter. Some will discover when they receive the replacement filter it has no o-ring to accompany it. Due to time constraints the o-ring from the old filter often gets transferred to the new filter causing complications later. I understand that some filters have been replaced unknowingly without the o-ring however, in those cases the engine simply did not start once the service was completed.

All new plastic lines, new pre-filter with new O-ring, and with new rubber lines from the engine to firewall.

IMHO this method addresses the cause to a large portion of 606 starting/performance complaints primarily during cold start and warm up.

Pre-filter # 601-092-01-05
O-ring # 601-997-01-48