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2000 Disco dies when hot, starts up again when cold.
G’day all! Long time follower of the site, first time member.
I’m completely stuffed with my Landy. It seems I’ve reached the extent of my knowledge. And so I’m asking for help.
Heres a quick list of the troubles just incase anyone comes across this same issue. She’ll start up fine, when cold. Once I get maybe 15min down the road. It happens. She starts stuttering and dies. Cranks but no spark, just fuel. There is a CEL but not all the time. It was a low voltage code which may be caused by the battery dying from cranking.
- I’ve replaced the CAS multiple times to no avail (3 different sensors, multiple brands) and spacers are installed correctly.
- I’ve checked the wires going to the CAS and they look ok.
- I’ve pulled the driver side fuse box and looked for poor solder.
- I’ve pulled the engine bay fuse box and looked for poor solder.
- I swapped around the ignition coil relays but it made no difference.
- I ran new wires to the CAS and it didn’t start at all, so I think there is something else running off those wires that needs the ecu signal.
Other than this the car is in great shape and was daily driven.
If if anyone can help, good onya, I’ll do anything to fix this issue. I’m pretty knowledgeable when it comes to automotive. Although I do not have access to the RAVE.
Thank you in advance!
Last edited by Dsport; Jan 3, 2019 at 05:33 PM.
Reason: More info
Thanks all, I picked up some proper shielded wire to run the new Crankshaft Position (crank angle) sensor wiring straight from the ECU. I will try that this evening after work and report back! As mentioned, I did check the wires, but they run back behind the engine and under the dash, it’s difficult to check for issues.
I will be using the instructions/diagram in the link above. (Thanks @robert.juric for digging that up!! Very helpful)
Well I ran new wires out to the crank angle sensor. And it wouldn’t start at all. I’m going to check the ecu pin out again, but I’m fairly certain the wires were matched correctly. If I swap the wires back it starts. I’ll be able to get to it again on Saturday and keep you posted.
So one thing I was concerned about, since I mostly posted that link in regards to wiring type. What type of Discovery are you driving? I went back and double checked the Rave, and paying closer attention to the linked post that diagram was for the Td5 engine.
Here is the diagram from the V8 section. I noticed the wiring colors and positions were different.
Also some relevant information from the Rave regarding wiring:
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.
And some failure info:
The CKP sensor can fail the following ways or supply incorrect signal:
Sensor assembly loose.
Incorrect spacer fitted.
Sensor open circuit.
Sensor short circuit.
Incorrect fitting and integrity of the sensor.
Water ingress at sensor connector
ECM unable to detect the software reference point.
Ferrous contamination of crank sensor pin/reluctor
In the event of a CKP sensor signal failure any of the following symptoms may be observed:
Engine cranks but fails to start.
MIL remains on at all times.
Engine misfires (CKP sensor incorrectly fitted).
Engine runs roughly or even stalls (CKP sensor incorrectly fitted).
Tachometer fails to work.
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.
The RAVE also states the adaptive values should be reset whenever a new CKP is installed.
Alright guys, I followed the attached diagrams and ran new wires out to the Crankshaft Postion Sensor (2000 petrol v8). I was unsecussful, it causes the truck not to start at all. Plug C0636. Wires 32, 45, 46. I checked for continuity at the ecu plug to the sensor plug for each of the 3 wires (pink/black, black/yellow, and shield wire). I checked my work maybe 6 times now. For some reason running new sensor wires straight from the ecu to the sensor does not work.
I’m going to re-solder the wires at the ecu and continue running the oem harness. I’ve delt with a simila situation on a Nissan where the wiring diagram does not give a full picture of the routing, I can only assume this is also the case here. Where anotha sensor/ecu shares one of the CPS wires, and bypassing the wires as I did, causes the vehicle not to run.
Im now back to square 1, although I did not think the harness was really the issue in the first place, I am unable to check it due to some unforeseen issue that isn’t included on the diagrams.
Alright guys. So I checked over the wiring again and again. The bypass I made (straight from ecu to crank position sensor) did not work. Same problem either way.
I noticed something however. When I bridge the pink/black wire to a chassis ground, a bunch of relays under the hood will start clicking. This will allow the truck to be started again! (Returns spark to the motor)
This pink/black wire grounding method won’t work when the truck is hot hot, but will allow the truck to start after it has cooled slightly. (When otherwise I would have needed to wait until it was dead cold to start again).
2000 Disco dies when hot, starts up again when cold.
