QuestionSo, does that mean that the ECU will cut out the engine before it overheats? I've never heard of that before. Or does it just mean it will not allow it to START when too hot? My car will die while driving, and also exhibit no-start when hot. I would think that a programmed response to heat to stop the engine could be dangerous while driving the car on public highways. I have had other suggestions to check the crank sensor because a failing signal there will in fact stop the engine. Apparently Bosch engine management cannot do without a crank signal. I took mine out and it was very crudded up with old coolant from a past head gasket leak. Does this also sound like a possibility to you? Thanks for your help, much appreciated.
Eric Brown
Followup To
Question -
I have a 1999 Discovery 2, Bosch engine management, and it stalls on the road while driving after 5 or so miles, and will not restart untill it gets to sit for 10 or 15 minutes. Even after a normal shutoff it will not restart hot untill it gets to sit 10 or 15 minutes. Every time I pump gas, I have to expect to be there at least 10 more minutes after pumping. I have checked fuel pressure, it is good, I have checked the strainer on the pump, it is clean, I have a new pump relay, and new ignition relay underhood and under dash. When I crank the engine hot and it refuses to start, I have noticed there is no spark. I do not know if it has injector pulses, I cannot get to the injector plugs. The problem is definitely heat related, the vehicle starts without fail when cold. Your help is greatly appreciated, thank you.
Eric Brown
Answer -
Hi Eric,
could be a temperature sensor failure, fuel temp sensor, or even thermostat. Have you looked at this as a possibility?
I know that part of the ECU's ignition sequence is to determine if the engine temperature is within tolerance. If above normal, the ECU cuts out the engine - hence no spark.
Check your temp sensors and thermostat...I hope that this is all that is wrong.
Best of luck,
JohnMc
AnswerHi Eric,
I the temperature sensor is only tested when the engine is being started. I agree, cutting out the fuel feed while driving is dangerous. SEE BELOW. I know that the front impact sensor can cut out the fuel feed to prevent engine fires in front-end collisions.
In your case, it seems that a heat sensor is triggering the ignition system from firing. You've got to determine if those sensors are 'open' full-time or not.
As for the crankcase sensor, its rare to find them at fault. You can clean it up but I doubt that its the cause.
A friend of mine as a 2003 corvette. He told me recently that a known security problem exists: the steering wheel can lock up while driving. Its a fault within the security control module. Not only does the wheel lock, the security module also cuts the fuel feed! Can you imagine trying to pass a transport truck and both your steering wheel locks AND your engines suddenly cuts out?
Anyway, I'm asking around to see if any other Disco II owner has had your problem. I'll keep you posted within the next few days.
Regards,
JohnMc
