rangerpilot
New Member
- Joined
- Nov 28, 2013
- Messages
- 54
- Reaction score
- 1
- Points
- 0
- Vehicle Year
- 1999
- Make / Model
- Ford
- Engine Size
- 4.0l V6
- Transmission
- Manual
Ok...so, I have troubleshooted so much the past few weeks regarding a P171 & P174 code. I am wanting to make sure I have covered all bases before I pull the intake. Here is a brief rundown:
1999 4.0 V6 OHV 4x4
1) Valve Cover Gaskets (and ECT sensor) replaced a few months ago
2) Not sure if they did the upper intake gaskets or not (I would only hope)
3) Checked all lines/hoses for vacuum leaks
3a) Vacuum Pressure Gauge (reads 21 in Hg. and drops to 5 psi with quick WOT)
3b) Starter fluid test
3c) Propane test (as far as I could reach around critical parts)
3d) Homemade Smoke test (using electronic fog machine on brake booster line)
4) New PCV valve
5) New O2 sensors (all three)
6) New Exhaust Gas Pressure Sensor and associated lines (I broke the old one)
7) Cleaned MAF sensor best I could
8) Did a voltage test on all leads to the MAF with no problems indicated)
9) Replaced Fuel Filter
10) Fuel Pressure holds a solid 40psi at idle and under high RPM
What else can I check? Could the fuel regulator or fuel pump be going bad and not delivering enough fuel to the rail? Any way to test EGR and related components?
It is both banks so I believe I can rule out the injectors as being the issue. I have driven like this for several months and can't narrow it down. I do have an occasional rough start (both cold and warm engine). It is very random.
I am out of ideas and really don't want to pull the intake if I don't have to.
Unrelated: I did a Block Test for Coolant Leaks (this is a totally separate issue however no problems noted there. Will be doing a compression check tomorrow as well as changing the plug wires.
Any more ideas?
1999 4.0 V6 OHV 4x4
1) Valve Cover Gaskets (and ECT sensor) replaced a few months ago
2) Not sure if they did the upper intake gaskets or not (I would only hope)
3) Checked all lines/hoses for vacuum leaks
3a) Vacuum Pressure Gauge (reads 21 in Hg. and drops to 5 psi with quick WOT)
3b) Starter fluid test
3c) Propane test (as far as I could reach around critical parts)
3d) Homemade Smoke test (using electronic fog machine on brake booster line)
4) New PCV valve
5) New O2 sensors (all three)
6) New Exhaust Gas Pressure Sensor and associated lines (I broke the old one)
7) Cleaned MAF sensor best I could
8) Did a voltage test on all leads to the MAF with no problems indicated)
9) Replaced Fuel Filter
10) Fuel Pressure holds a solid 40psi at idle and under high RPM
What else can I check? Could the fuel regulator or fuel pump be going bad and not delivering enough fuel to the rail? Any way to test EGR and related components?
It is both banks so I believe I can rule out the injectors as being the issue. I have driven like this for several months and can't narrow it down. I do have an occasional rough start (both cold and warm engine). It is very random.
I am out of ideas and really don't want to pull the intake if I don't have to.
Unrelated: I did a Block Test for Coolant Leaks (this is a totally separate issue however no problems noted there. Will be doing a compression check tomorrow as well as changing the plug wires.
Any more ideas?
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