Q: Flames coming from the tailpipe and rough idle

Hello there, many common faults will cause your 1984 Dodge D250 to have a rough engine idle and have flames coming from the exhaust. When flames are seen coming form the exhaust it is most often due to unburnt fuel in the exhaust system, or improper valve timing. Either of these faults can be rather serious and have many different causes. The most common is faulty ignition timing, leaking injector, fuel pump, spark plugs, plug wires, and the cap & rotor. This vehicle should not be driven as the flames can cause a backfire that has the potential to damage the engine. A qualified Technician such as one from YourMechanic will be able to diagnose your rough idle and flame from the exhaust.