Sounds like a internal fuel leak and a gummed up ics valve. Try running a couple cans of techron through it, reset the base CO and cleaning the ics. (along with some new plugs and secondary ignition inspection)
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.