Engine Mechanical problem
1972 Ford LTD V8 Two Wheel Drive Automatic 240000 miles
I have a 1972 Ford LTD 400 V8 and when it idles at times (more often then not) It makes a chugging noise and will Idle really low and kill itself, and now when I go down hills it backfires without my foot on the gas. Can anyone please help me with this?
A backfire could be a leak in the exaust system and leaning out. The cuggin noise is probably due to either the emissions being disconnected and the egr plate under the carb used to get holes in it as well as the egr leads in teh intake get clogged. You probably need a carb overhaul though as the alcohol in the fuel has destroyed the accelerator pump as well as the diaphragm for the power vavle. 400's did have valve guide problems as well so it may be beneficial to pull the heads and get the valves ground and newer valve seats installed.