Ford Focus 1.6 diesel 2005 cuts out randomly, won't start then will start

boruho

The car engine randomly cuts out. It has happened with the engine hot or cold. After 2 or 3 minutes it will restart but then likely to die again. This happens in clusters. Once the car is left of some time it can drive 100km before happening again. The garage has changed the fuel filter, otherwise is at a loss. I have done a search on boards.ie and other boards that suggests the problem could be:
- Alarm immobilizer
- Vacuum leak / air getting into fuel line
- Bad earth connection
- Loose connection into fuse box
- Cam / crank shaft sensor
Can anyone help? I am hoping that the symptoms are diagnostic to someone. It is driving me crazy.

honda boi

boruho wrote: »

The car engine randomly cuts out. It has happened with the engine hot or cold. After 2 or 3 minutes it will restart but then likely to die again. This happens in clusters. Once the car is left of some time it can drive 100km before happening again. The garage has changed the fuel filter, otherwise is at a loss. I have done a search on boards.ie and other boards that suggests the problem could be:
- Alarm immobilizer
- Vacuum leak / air getting into fuel line
- Bad earth connection
- Loose connection into fuse box
- Cam / crank shaft sensor
Can anyone help? I am hoping that the symptoms are diagnostic to someone. It is driving me crazy.

Have you had the codes read using an obd?

mullingar

Id do a live scan of the fuel pressure readings during a drive. If thats OK, one thing I remember reading something like this before, IIRC it turned out to be a faulty dash clock as its part of the immobiliser system

boruho

The garage read the codes and found nothing. The mechanic thinks it is most likely to be the cam or crankshaft sensor and will replace both. He does not think it is a faulty clock or immobilizer because there is no flickering nor sign of malfunction. Nor does he think it is fuel pressure. I will give an update on what happens.

two wheels good

You mention fuel pressure is okay but I'll still suggest fuel pump.
Listen for it priming when ignition is on. Does it prime when problem is present. Try a few sharp taps on the pump cover.
Could the tank vent be blocked? Try opening the fuel cap.

I'm not familiar with that car model but a similar problem with a Citroen. The pump cover is proabably under the rear seat.

George Dalton

The instrument clusters in that shape Focus can fail and give those exact symptoms.

Next time the car cuts out and fails to start try hitting the top of the dashboard above the clocks and then try to start the car. If it starts up straight away then it is most likely a cluster issue.

Alternatively you may be able to provoke the problem with the same trick, if the car cuts out when you hit the dashboard then you also know the cluster is the problem.

They can be repaired for small money if that does turn out to be the problem.

mullingar

two wheels good wrote: »

You mention fuel pressure is okay but I'll still suggest fuel pump.
Listen for it priming when ignition is on. Does it prime when problem is present. Try a few sharp taps on the pump cover.
Could the tank vent be blocked? Try opening the fuel cap.

I'm not familiar with that car model but a similar problem with a Citroen. The pump cover is proabably under the rear seat.

There is no pre-lift fuel pumps on those Focus's, only the main high pressure pump which starts to pump as soon as you crank it as its powered from the timing belt.

boruho

George Dalton wrote: »

The instrument clusters in that shape Focus can fail and give those exact symptoms.

Next time the car cuts out and fails to start try hitting the top of the dashboard above the clocks and then try to start the car. If it starts up straight away then it is most likely a cluster issue.

Alternatively you may be able to provoke the problem with the same trick, if the car cuts out when you hit the dashboard then you also know the cluster is the problem.

They can be repaired for small money if that does turn out to be the problem.

I tried hitting the dashboard when running but the engine did not cut out. The only other possibility I can think of is damage to the electrics when pulling the car out of the bush one day, and doing some damage to the plastic bumper on the left side at the front. An electric box came loose. The problem started after that. Anyone know what cables run through that box?

George Dalton

The Engine ECU is in that box so it could be related.

boruho

An update - changing the crank and cam shaft sensors solved the problem.