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Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
- Joined
- Sep 20, 2009
- Messages
- 34,623
- Reaction score
- 3,613
- Points
- 113
- Location
- Dillsburg PA
- Vehicle Year
- 1987
- Make / Model
- Ford
- Engine Type
- 4.0 V6
- Engine Size
- 4.0
- Transmission
- Manual
- 2WD / 4WD
- 4WD
- Tire Size
- 31X10.50X15
I would also suspect timing chains if the concern was consistent across the temp range. He said it's fine once it warms up. The O2 code is not part of your driveability issue, it's just for the heater.
The fact that all of bank one is involved and there is a code that seems to relate to fuel pressure makes me suspicious of the fuel system. The 4.0 uses a returnless system, and the fuel comes into the rail on the bank 2 side, meaning bank 1 gets fed last. Low fuel pressure will have a disproportionate effect on bank 1. I would do a fuel pressure test to start.
You can also swap all your plug wires side to side at the coil and recheck for the misfire codes in a day or two, see if they changed cylinders. That would point to an issue in the coil pack.
The fact that all of bank one is involved and there is a code that seems to relate to fuel pressure makes me suspicious of the fuel system. The 4.0 uses a returnless system, and the fuel comes into the rail on the bank 2 side, meaning bank 1 gets fed last. Low fuel pressure will have a disproportionate effect on bank 1. I would do a fuel pressure test to start.
You can also swap all your plug wires side to side at the coil and recheck for the misfire codes in a day or two, see if they changed cylinders. That would point to an issue in the coil pack.
