csuengr
New Member
- Joined
- August 29, 2011
- Messages
- 5
- Reaction score
- 0
- City, State
- Loveland, CO
- Year, Model & Trim Level
- 1997 explorer 5.0
I have a 1997 5.0 and two weeks ago it started missing when loaded. A week ago it started missing and backfiring through the throttle body, but only under load. Idle is smooth, quiet, and at the correct rpm. No codes, in case one asks.
Here is what I have done.
New coil packs.
Pulled all vacuum hoses off manifold, plugged ports.
Put in spare ECU.
Sprayed carb cleaner around upper intake and lower, no idle change.
New fuel pump and filter. Old pump would drop to ~35 psi when engine was reved. Fuel pressure is now rock steady.
Injectors were pulled and flow tested. All were with 1.5 mL of each other.
Sprayed water (while dark out) around (old) coil packs and ignition wires and there were no sparks
Pulled spark plugs. All looked perfect.
Cleaned MAF.
Graphed both pre-cat O2 sensors and they tracked virtually the same and the graphs look normal.
None of the above had any affect on the way it runs. One interesting note, I pulled the plug wire of the coil pack for #1 cylinder and was rewarded with two codes. P0171 and P0174. Bank one too lean and bank two too lean. I duno.
What I haven't done.
Compression check.
Replace spark plugs.
Replace ignition wires.
I am at a loss right now. This issue has already cost me one camping trip and it's about to do in another. Help please.
Here is what I have done.
New coil packs.
Pulled all vacuum hoses off manifold, plugged ports.
Put in spare ECU.
Sprayed carb cleaner around upper intake and lower, no idle change.
New fuel pump and filter. Old pump would drop to ~35 psi when engine was reved. Fuel pressure is now rock steady.
Injectors were pulled and flow tested. All were with 1.5 mL of each other.
Sprayed water (while dark out) around (old) coil packs and ignition wires and there were no sparks
Pulled spark plugs. All looked perfect.
Cleaned MAF.
Graphed both pre-cat O2 sensors and they tracked virtually the same and the graphs look normal.
None of the above had any affect on the way it runs. One interesting note, I pulled the plug wire of the coil pack for #1 cylinder and was rewarded with two codes. P0171 and P0174. Bank one too lean and bank two too lean. I duno.
What I haven't done.
Compression check.
Replace spark plugs.
Replace ignition wires.
I am at a loss right now. This issue has already cost me one camping trip and it's about to do in another. Help please.
