[prarieschooner]

How old is the Fuel? If the Fuel is old it could contribute to problems with these older 2 Stroke Diesels.
When I purchased my '82 after it wasn't used for an extended period of time I purchased a case of Fuel Filters to help solve these types of problems. I simply changed the Fuel Filter every few hours of operation, this may or not help. Changing the Fuel Filter will help keep any contamination from organisms out of the Fuel System while you use up the old Fuel. The other alternative is to have the Fuel Tanks Drained and Cleaned, which would be advisable if the Fuel is really bad (where was the Coach when you bought it). I agree with the others "use the puppy" take the Newell out for a ride and get new Fuel. Take the Coach out and get the Diesel warm for a few hours these old gals need to be operated and not just around town. Check another post stating that you should "drive it like you stole it", it may help. Our '82 is running much better after logging almost 1500 miles and getting better.
By the way there is a group of Newells going to Creede, CO in August, great excuse to go somewhere