If you truck won't start and therefore is not throwing any codes how would you know if the issue is the CMP Sensor?
Camshaft Position (CMP) Sensor
- Thread starter wrldky
- Start date
I don't know the specifics of rovers, new owner, I'm learning. I am not sure of the operating strategy of the ECM in rovers. Some of the newer GM engines I see don't even use a cam sensor anymore.
Generally speaking, no spark and injectors not firing is crank sensor. Cam sensor just for position of cam, faster start-up, redundancy in my opinion. I have seen engines that continue to run without camshaft input. Cam sensor completely disconnected and engine will still start and run.
Speaking from experience, I bought a 2004 D2, had it for less than a week and it stalled one day pulling into my driveway, started right up. An hour later it would not start. Had no spark. A few minutes later it started. This went on over the next day or two and finally would not start. No spark, injectors not firing. Never threw a code, never saw a check engine light even when it quit as I was driving. I scanned it with snap-on modis scan tool. It would crank and not start and never had fault code. Only clue that I saw on the scanner was zero rpm when cranking.
Replaced crank sensor, that was fun (not), no issue since then.
If you want to know definitively, you will need an oscilloscope and you will back probe the cam signal to ecm and watch the waveform on scope and compare it to a reference waveform. A scan tool that has graphing ability will do this too but I have seen where ecm data and raw data can be different so in my opinion raw data (back probing the sensor) is better.
Generally speaking, no spark and injectors not firing is crank sensor. Cam sensor just for position of cam, faster start-up, redundancy in my opinion. I have seen engines that continue to run without camshaft input. Cam sensor completely disconnected and engine will still start and run.
Speaking from experience, I bought a 2004 D2, had it for less than a week and it stalled one day pulling into my driveway, started right up. An hour later it would not start. Had no spark. A few minutes later it started. This went on over the next day or two and finally would not start. No spark, injectors not firing. Never threw a code, never saw a check engine light even when it quit as I was driving. I scanned it with snap-on modis scan tool. It would crank and not start and never had fault code. Only clue that I saw on the scanner was zero rpm when cranking.
Replaced crank sensor, that was fun (not), no issue since then.
If you want to know definitively, you will need an oscilloscope and you will back probe the cam signal to ecm and watch the waveform on scope and compare it to a reference waveform. A scan tool that has graphing ability will do this too but I have seen where ecm data and raw data can be different so in my opinion raw data (back probing the sensor) is better.
Rob, I appreciate it. Unfortunately the crankshaft sensor is new. Also I should have mentioned I just replaced the front timing cover and radiator. So the only thing i really touched (I believe) that would prevent the car from starting is the camshaft sensor. I have read that the truck will not start if this is not working. Any advice?
Just start like you never did any of the work you described. You need spark, fuel pressure and injector pulses, and compression. and its all gotta be timed. So we can eliminate timed if you didn't mess with the timing chain.
Do you think you could have bumped anything hard enough to trip the inertia switch?
I checked the inertia switch and it seems fine. I never found out definitively if the truck would start with a bad camshaft sensor. Opinions seem to be all over the place and a lot of people seem to confuse to Camshaft with the crankshaft sensor. I think I will spring for a new sensor just in case. Which brings me to the next question. Has anyone used an aftermarket Camshaft sensor. Genuine Land Rover and Eurospare are really expensive. Has anyone else used another brand with success?
There was a nice tread about using generic camshaft position sensors:
https://discoweb.org/showthread.php?t=92043
https://discoweb.org/showthread.php?t=92043
PM,
That was a good thread but I was not looking to make an adapter. I'm not sure if the cam sensor is my problem will know know more tonight. Thanks for the help.
That was a good thread but I was not looking to make an adapter. I'm not sure if the cam sensor is my problem will know know more tonight. Thanks for the help.
New Camshaft Sensor and truck is still not working. Fuel pump and Crankshaft sensor are both about 6 months old. Any advice would be great this is very frustrating.
Check for spark, fuel psi , and injector pulses. I would have been very surprised if the cam sensor fixed anything. If you have spark and fuel psi and injector pulses check compression. Only buy parts when you fully understand what that part is or isn't doing.
Discostew you are correct in that the cam sensor did not change anything. Still do not know the answer though. Back to the basics.
