I have a 91 LX 5.0, all stock except the BBK CAI, Shorties and full exhaust no cats. Symptoms are rough idle(sounds cammed), if I give it a little gas it will jerk/stumble/sputter then stall if I keep at it. If I go full throttle it can rev up a little bit. I can’t even drive it, I’ve been chasing this problem for almost two weeks. I pulled the codes: KOER-12, 21, 26, 33, 42, 92, 18
KOEO-11, 63
Things I tried so far:
Code 12-I swapped the IAB, its getting voltage, cleaned contacts, new tps calibrated to .98, it’s getting the 5 volts
Code 21-cleaned the ECT, cleaned contacts
Code 26-New MAF, tried different clocking positions, cleaned contacts, it’s getting 12 volts, ground is good, resistance is good To the pcm connector.
Code 33-EGR getting voltage, diaphragm is good, even blocked off vacuum line to rule out leaks, swapped EGR
Code 42/92-checked FPR for leaking fuel;good, fuel filter, fuel pressure good; used gauge at valve between 30-40 psi at idle with vacuum line off, injector voltage good, used stethoscope to listen for clicking it was good, checked ohms on injectors; all are the same, back probed pin at ecm 43&29 for 02 sensors;reading between .2-.9, cleaned contacts for 02 sensors. Fuel pump sounds good when key is on the on position.
Code 18-timing was advancing with spout connector in, timing set at 12 degrees, check the wire with the 22k resistor to ecm connector is all good, changed wires, distributer, TFI module, checked all ground especially the one near the battery, changed cap and rotor. Checked the resistance for the TFI connector wires to the ecm harness and all checked out. Also ok apart the salt and pepper shakers, spread the pins a little bi for better contact.
I’m getting a proper charge from the alternator, I’m stumped guys. I pulled the plugs and noticed they were pitch black. It’s definitely running super rich, pretty much sucking the fuel like crazy. Now when I first acquired the car, it had a bad TB gasket and you could hear the hissing. Since then I fixed the leaks but surprisingly, no change in idle or drivability.
KOEO-11, 63
Things I tried so far:
Code 12-I swapped the IAB, its getting voltage, cleaned contacts, new tps calibrated to .98, it’s getting the 5 volts
Code 21-cleaned the ECT, cleaned contacts
Code 26-New MAF, tried different clocking positions, cleaned contacts, it’s getting 12 volts, ground is good, resistance is good To the pcm connector.
Code 33-EGR getting voltage, diaphragm is good, even blocked off vacuum line to rule out leaks, swapped EGR
Code 42/92-checked FPR for leaking fuel;good, fuel filter, fuel pressure good; used gauge at valve between 30-40 psi at idle with vacuum line off, injector voltage good, used stethoscope to listen for clicking it was good, checked ohms on injectors; all are the same, back probed pin at ecm 43&29 for 02 sensors;reading between .2-.9, cleaned contacts for 02 sensors. Fuel pump sounds good when key is on the on position.
Code 18-timing was advancing with spout connector in, timing set at 12 degrees, check the wire with the 22k resistor to ecm connector is all good, changed wires, distributer, TFI module, checked all ground especially the one near the battery, changed cap and rotor. Checked the resistance for the TFI connector wires to the ecm harness and all checked out. Also ok apart the salt and pepper shakers, spread the pins a little bi for better contact.
I’m getting a proper charge from the alternator, I’m stumped guys. I pulled the plugs and noticed they were pitch black. It’s definitely running super rich, pretty much sucking the fuel like crazy. Now when I first acquired the car, it had a bad TB gasket and you could hear the hissing. Since then I fixed the leaks but surprisingly, no change in idle or drivability.
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