- Joined
- Jan 13, 2014
- Messages
- 335
- Reaction score
- 12
- Points
- 18
- Vehicle Year
- 2002
- Make / Model
- Ford
- Engine Size
- 5.0
- Transmission
- Automatic
Think I'm getting ready to abandon the current 5.0 in my Ranger and build another -- have been going nuts trying to track down a seemingly RPM related miss and sub-standard fuel economy.
It's a 1996 5.0 in my 02 Ranger.
Engine was refreshed with new rings/bearings/valve springs etc -- internals all mic'd to near new spec.
Diff is an Expo 8.8 with 3.27:1 gears, has me at about 2000 rpm at 65 mph.
No check engine light/fault codes
130/135 psi compression cold/dry across all 8 cylinders
Long and short term fuel trims hover around 0%
Miss seems at it's worst between 1500 and 1700 RPM
Idles with 23" to 24" of vacuum
Fuel pressure runs 29 psi with vacuum applied, 38 psi without vacuum -- tried an adjustable FPR setting the pressures at 35 and 45 psi (LTFT's moved to -7%)
0 PSI of exhaust pressure at the front O2 sensors at 50 mph.
Two different sets of ignition wires
Two different sets of spark plugs
Two different sets of ignition coils
Two different ECU's
Two different cam position sensors
Two different crank position sensors
Two different sets of fuel injectors.
Two different air filters
Cam timing has been verified -- cam position sensor timed while the timing cover was off the engine.
Tried different O2 sensors and swapping them side for side.
Engine temp sensor and coolant temp sensor appear to agree with the thermostat.
PCM seems to correctly toggle between open and closed loop.
TPS shows very smooth readings from fully closed to fully open
Think only the MAF, IAC and TPS are original
So, two questions: Does anyone have any ideas what I might have missed?
And, would a GT40P based '97 5.0 still support the "through the intake" EGR of my '96 manifolds? I've found a great deal on a reasonable miles external EGR 5.0.
It's a 1996 5.0 in my 02 Ranger.
Engine was refreshed with new rings/bearings/valve springs etc -- internals all mic'd to near new spec.
Diff is an Expo 8.8 with 3.27:1 gears, has me at about 2000 rpm at 65 mph.
No check engine light/fault codes
130/135 psi compression cold/dry across all 8 cylinders
Long and short term fuel trims hover around 0%
Miss seems at it's worst between 1500 and 1700 RPM
Idles with 23" to 24" of vacuum
Fuel pressure runs 29 psi with vacuum applied, 38 psi without vacuum -- tried an adjustable FPR setting the pressures at 35 and 45 psi (LTFT's moved to -7%)
0 PSI of exhaust pressure at the front O2 sensors at 50 mph.
Two different sets of ignition wires
Two different sets of spark plugs
Two different sets of ignition coils
Two different ECU's
Two different cam position sensors
Two different crank position sensors
Two different sets of fuel injectors.
Two different air filters
Cam timing has been verified -- cam position sensor timed while the timing cover was off the engine.
Tried different O2 sensors and swapping them side for side.
Engine temp sensor and coolant temp sensor appear to agree with the thermostat.
PCM seems to correctly toggle between open and closed loop.
TPS shows very smooth readings from fully closed to fully open
Think only the MAF, IAC and TPS are original
So, two questions: Does anyone have any ideas what I might have missed?
And, would a GT40P based '97 5.0 still support the "through the intake" EGR of my '96 manifolds? I've found a great deal on a reasonable miles external EGR 5.0.
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