QuestionI bought the truck used 47000 on the odom. Drivability probs: sounds like it misses on idle and while driving at a constant speed. Intermittent fuel consumption in short distances and poor power. No trouble codes, mil light isnt illuminated. Replaced spark plugs (all 8) and wires, fuel pump and sending unit, pre-o2 sensor, coolant temp sending unit and sensor, new air filter... I have an education in automotive technology but not any diagnostic equipment.. Ive taken it to the Ford dealership 3 times and they say there isnt a problem... Im stumped and so is all of my tech buddies thats put some thought into it, any help will be appreciated.
AnswerWell, when up against a problem like this i always start at the basics.
Does the CEL work? and is there any codes stored? KOEO and KOER tests pass ok?
Vacuum readings at idle and 2000 rpm
Exhaust back pressure test
Vac leaks
Fuel pressure and delivery tests
Engine compresssion and Cylinder leakage tests
Ingnition timing and advance.
Lets see what these produce
Also , upon searches, i have found 5 out of 7 similar cases were a result of timing belt mis alignment :)
