i have the chance to pick up a 85 ltd with 44,000mi. it has sat for 3+yrs. the says it ran when he inhertied but tried to start recently and was rough and missing, he says the fuel was old. he thinks it is a stuck valve, i will look at it friday. is there a way i can determine if it is a valve or just dirty fuel or plugged injector? he wants 650.00 which i could use for parts to fix up mine or fix up and give to son or sell.