My 00 Disco and has had some strange problems. Around 4 months ago, while I was overseas, my wife started and drove the Disco to a gas station 15 mins away from our home. She shut it down, filled it up and it would not restart. Being late for an appoinment she went on foot and return around an hour later. The disco started fine. She drove it home and did not use it again. I returned and tried to start it, it made a clicking noise. So I pulled the starter, tested it and it worked fine. So I charged the battery and it started fine. Then after about 30 mins running it died again. So I jumped it and took it to auto zone, they check the alternator and battery and both checked out. I drove it to the store and turned it off to go inside, when I came out it would not start. The next morning I returned to the store and it started fine. There are no error codes and no indicator lights. When it wont start there is no spark. Once it sits for an hour or more it starts fine. Please help.

 

are you 100% certain your wife used 93 octane gas while you were gone?

 

Stalling or difficulty with starting, but starting some time later is a crank sensor.
PM me your tele number if you have any more questions.

 

Crank sensor, when it gets hot it fails, cools off and it works again.
The crank sensor controls the spark.
It would not start when you came home because the battery was dead.

 

Thanks for the replies. I thought it must be some sort of sensor cutting out the spark. I will remove and check the sensor you mentioned. We only have 92 octane available in Nevada and I am sure she used the right gas. To be sure I understand your recommendations, the sensor fails once it is warm and works once the engine has cooled correct? That would fit all the symptoms. Each time it has taken a couple hours to restart. Our Disco has 130K miles, so is this a common problem or should I look for some cause to prevent this in the future? Thanks again.

 

Mike,
It does not start once I turn it off. I checked the spark and there is no spark right after I shut it down. Then a few hours later it starts right away. No codes and no warning lights. Once it is started it runs great. I am going to check the crank sensor, is there anything else you recommend.

 

There is no way to check the crank sensor, either it works or is doesnt.
Replace it, $70 at AutoZone.

 

can you not put a multimeter on it and see if it gives an ohm reading within spec?

 

I do not know.
And even if you could how are you going to reproduce this with the CKS hot?
Are you going to remove it and then heat it on your wifes stove?
Then put it back into the truck and hope it is still good?
It is a replace when it goes bad item and there is no way that I know of to bench test it.

 

This may help:

Crankshaft speed and Position (CKP) sensor (C0168)

The CKP sensor is located towards the rear of the engine below cylinder number 7, with its tip adjacent to the outer circumference of the flywheel. The CKP sensor is the most important sensor on the vehicle and without its signal the engine will not run. The signal produced by the CKP sensor allows the ECM to determine crankshaft angle and speed of rotation. The ECM uses this information to calculate ignition timing and fuel injection timing.The CKP sensor works as a variable reluctance sensor. It uses an electromagnet and a reluctor ring to generate a signal. As the reluctor ring passes the tip of the CKP sensor the magnetic field produced by the sensor is cut and then re-instated. The ECM measures the signal as an ac voltage.The output voltage varies in proportion to engine speed. The reluctor ring has a set tooth pattern, 60 teeth are spaced at 6 degrees intervals and are 3 degrees wide, two teeth are removed to provide a reference mark at 60 degrees BTDC for number 1 cylinder.
There is no back up strategy or limp home facility if this sensor fails, the engine does not run.
Input/Output
Because of the nature of its operation the CKP sensor does not require any electrical input source. The CKP sensor is a 3 pin variable reluctance sensor generating its own electrical output. The 2 output sources from the sensor are earthed via pin 46 of connector C0636 of the ECM and sensor output is via pin 32 of connector C0636 of the ECM. This output is in the form of an ac voltage waveform. The 3rd pin is used by the ECM as an earth screen, this screen protects the integrity of the CKP sensor signal to ensure that outside electrical interference is eliminated, it is controlled via pin 45 of connector C0636 of the ECM. The ac voltage generated from the CKP sensor is relative to engine speed.

Typical CKP sensor output
The above readings are dependent upon correct air gap between the tip of the CKP sensor and the passing teeth of the reluctor ring. The correct air gap between the tip of the CKP sensor and the passing teeth of the reluctor ring can be set by the correct fitting of a spacer as follows:
l 9.2 mm spacer for vehicles with manual gearbox fitted.
l 18 mm spacer for vehicles with automatic gearbox fitted.
It is vital that the correct air gap is maintained, if the air gap becomes too wide the CKP signal becomes too weak,causing possible engine misfires to occur.

The CKP sensor can fail the following ways or supply incorrect signal:

l Sensor assembly loose.
l Incorrect spacer fitted.
l Sensor open circuit.
l Sensor short circuit.
l Incorrect fitting and integrity of the sensor.
l Water ingress at sensor connector
l ECM unable to detect the software reference point.
l Ferrous contamination of crank sensor pin/reluctor

In the event of a CKP sensor signal failure any of the following symptoms may be observed:

l Engine cranks but fails to start.
l MIL remains on at all times.
l Engine misfires (CKP sensor incorrectly fitted).
l Engine runs roughly or even stalls (CKP sensor incorrectly fitted).
l Tachometer fails to work.
l Flywheel adaption reset – ferrous contamination
If the CKP sensor fails while the engine is running the engine will suddenly stall, this is because the CKP sensor has no backup strategy. If this happens the ECM will produce a fault code that it can store in its memory. If the engine is not running when the CKP sensor fails, the vehicle will crank but will be unlikely to start, and no fault code will be
generated. In this instance the MIL lamp will remain illuminated and the tachometer will fail to read.

It is vital that the CKP sensor output wires are not reversed (i.e. the connector is fitted incorrectly) as this will cause
a 3 degrees advance in ignition timing. This happens because the ECM uses the falling edge of the signal waveform as its reference or timing point for each passing tooth on the reluctor. Whenever a new crankshaft position sensor is fitted or the flywheel is removed, the adaptive values will have to be reset, using TestBook.
Should a malfunction of the component occur, the following fault codes may be evident and can be retrieved by TestBook:

P Code J2012 description Land Rover description

P0335 Crankshaft position sensor a circuit malfunction Reference mark outside search window for more thantwo revs, with engine speed above 500 rev/min

P0336 Crankshaft position sensor a circuit range/
performance Incorrect number of teeth detected +- 1 tooth between reference marks with engine speed above 500 rpm