New-to-me truck. Has run okay at times. 1994 Mazda B4000 4.0 liter 4x4 Ranger clone, 130k.
MAF sensor looks great, spritzed with genuine MAF cleaner spray. Is a rebuilt.
DPFE sensor is new plastic. Removed, shook it, don't hear any water. (They say condensation curses the things.) Found a bum vacuum line leading to it, fixed.
Has nearly new (from PO) nice blue Belden plug wires. I swapped plugs, had copper champions, put in copper bosches. Old plugs all looked the same; nice.
Exhaust smells gassy. More an unburned gas than a rich, black-soot-smoke gas. I tried adding some unlit propane torch gas in the intake while it idled, no better.
A spark test with an inline timing light and an old spark plug with the electrode broke off (for a wider gap) laying on a ground had blue spark on all three coil packs with no misses.
Fuel pump doesn't sound like it's struggling.
Truck idles okay (but sometimes you can pick up a miss) and goes WOT okay but is juddery at mid-throttle, cold or warm, damp or dry. Is a stick shift so you feel it.
Codes: Love 'em. Pulled them before I started messing with things:
In order: 51,25,22,11,72,17,31,76,17,71,72,17,31,76,17, done. Not a lot of sense there.
Tried various unplugged sensors one at a time. MAF, coolant temp, air temp, DPFE, plugged EGR vacuum. No help.
Thinking of a compression test, but not eager to snake the stuff behind the AC box on the passenger side. May also be able to pull off a fuel pressure test if I can find the equipment.
So... who knows fords of a certain vintage?
This has coil pack ignition, post TFI module era.
MAF sensor looks great, spritzed with genuine MAF cleaner spray. Is a rebuilt.
DPFE sensor is new plastic. Removed, shook it, don't hear any water. (They say condensation curses the things.) Found a bum vacuum line leading to it, fixed.
Has nearly new (from PO) nice blue Belden plug wires. I swapped plugs, had copper champions, put in copper bosches. Old plugs all looked the same; nice.
Exhaust smells gassy. More an unburned gas than a rich, black-soot-smoke gas. I tried adding some unlit propane torch gas in the intake while it idled, no better.
A spark test with an inline timing light and an old spark plug with the electrode broke off (for a wider gap) laying on a ground had blue spark on all three coil packs with no misses.
Fuel pump doesn't sound like it's struggling.
Truck idles okay (but sometimes you can pick up a miss) and goes WOT okay but is juddery at mid-throttle, cold or warm, damp or dry. Is a stick shift so you feel it.
Codes: Love 'em. Pulled them before I started messing with things:
In order: 51,25,22,11,72,17,31,76,17,71,72,17,31,76,17, done. Not a lot of sense there.
Tried various unplugged sensors one at a time. MAF, coolant temp, air temp, DPFE, plugged EGR vacuum. No help.
Thinking of a compression test, but not eager to snake the stuff behind the AC box on the passenger side. May also be able to pull off a fuel pressure test if I can find the equipment.
So... who knows fords of a certain vintage?
This has coil pack ignition, post TFI module era.
