Hey guys,
Found this forum, maybe someone here can help me out. I'll try to keep it short and sweet.
Car is a 95 sunfire, 2.2, 3spd, 322k km.
I recently replaced the motor as the old one had a cracked head/blow gasket. I thought it had dropped a cylinder when it started horribly missing and bucking, raw gas going through the exhaust etc. Bought a used motor out of a 95 sunfire, 175 on compression. Slapped it in, still missed at idle, and under load.
Driving around the CEL came on, but would clear as soon as i shut it off. Managed to scan the codes and it came up with about a dozen: MAP, TPS, O2, IAT, 2 Quad Driver codes etc. Swapped upper intake plenum to a known working one, swapped ECU. Driving around, still lean misfire/ignition misfire. CEL came back this time with only MAP High Vacuum, and O2 Lean.
Checked Fuel Pressure: 43-45psi good.
Replaced Ignition Coil and wires to working one. Ignition misfire gone.
Deleted Catalytic Converter, Manifold to muffler only - No change
When the O2 sensor is unplugged it runs...ok, CEL will eventually come on stating O2 Lean condition..this makes sense. Runs very rich which also makes sense. First start of the morning idle is very rough and hunts slightly. Plug the O2 sensor in, it runs even worse: MASSIVE Lean misfire, can barely get it to 50km/h (~30mph).
What the hell?!
Found this forum, maybe someone here can help me out. I'll try to keep it short and sweet.
Car is a 95 sunfire, 2.2, 3spd, 322k km.
I recently replaced the motor as the old one had a cracked head/blow gasket. I thought it had dropped a cylinder when it started horribly missing and bucking, raw gas going through the exhaust etc. Bought a used motor out of a 95 sunfire, 175 on compression. Slapped it in, still missed at idle, and under load.
Driving around the CEL came on, but would clear as soon as i shut it off. Managed to scan the codes and it came up with about a dozen: MAP, TPS, O2, IAT, 2 Quad Driver codes etc. Swapped upper intake plenum to a known working one, swapped ECU. Driving around, still lean misfire/ignition misfire. CEL came back this time with only MAP High Vacuum, and O2 Lean.
Checked Fuel Pressure: 43-45psi good.
Replaced Ignition Coil and wires to working one. Ignition misfire gone.
Deleted Catalytic Converter, Manifold to muffler only - No change
When the O2 sensor is unplugged it runs...ok, CEL will eventually come on stating O2 Lean condition..this makes sense. Runs very rich which also makes sense. First start of the morning idle is very rough and hunts slightly. Plug the O2 sensor in, it runs even worse: MASSIVE Lean misfire, can barely get it to 50km/h (~30mph).
What the hell?!