Try a professional fuel injection cleaning. Those older 3.1 motors had a need for this every so often. When bad enough we have had to replace injectors.6th cylinder the most common.
Also have you been using coolant at all on this?
Another good pratice is cleaning the air intake system. The throttle plates and intake valves do get a fair amount of carbon on them.
Thursday, March 20th, 2008 AT 6:41 PM