invain
01-02-2009, 12:00 PM
I know I already have a thread here asking about injector wires, but I figured I'd start a new one since that wasn't the problem and I'm stuck again.
Been having a problem with a cylinder not firing in my 98' Nissan 240sx. First thing I checked was spark, which was all good. I know compression is fine in that cylinder, and the plug was dry when I pulled it so I know fuel is the problem. Checked/swapped injectors and found that wasn't the problem. I found very low voltage at the injector plug so we ripped into the harness and found a small short in the 12v wire to the injector. Fixed that and now the voltage is fine. However, the injector is still not receiving a ground signal from the ecu. We tested continuity in the ground wire all the way to the ecm harness connector and it was fine. I have a second ecu for the car so we swapped that in which changed nothing as well, which rules out an ecu problem.
The only thing left I can think of is the Cam position sensor not working correctly. We tested contiunity in all the wiring for the sensor following the fsm instructions and found on problems. Now I need to know if there's any way to check if the cmps (cas) is actually sending the correct signals or not.
Could a faulty cam position sensor cause only one cylinder to misfire/not fire? I really have no clue what else the problem could be. This problem has been real intermittent which made me think it was originally a wiring problem, but we've tested pretty much every connection possible and they're all fine.
Been having a problem with a cylinder not firing in my 98' Nissan 240sx. First thing I checked was spark, which was all good. I know compression is fine in that cylinder, and the plug was dry when I pulled it so I know fuel is the problem. Checked/swapped injectors and found that wasn't the problem. I found very low voltage at the injector plug so we ripped into the harness and found a small short in the 12v wire to the injector. Fixed that and now the voltage is fine. However, the injector is still not receiving a ground signal from the ecu. We tested continuity in the ground wire all the way to the ecm harness connector and it was fine. I have a second ecu for the car so we swapped that in which changed nothing as well, which rules out an ecu problem.
The only thing left I can think of is the Cam position sensor not working correctly. We tested contiunity in all the wiring for the sensor following the fsm instructions and found on problems. Now I need to know if there's any way to check if the cmps (cas) is actually sending the correct signals or not.
Could a faulty cam position sensor cause only one cylinder to misfire/not fire? I really have no clue what else the problem could be. This problem has been real intermittent which made me think it was originally a wiring problem, but we've tested pretty much every connection possible and they're all fine.