Problem with a stalling engine

I WAS interested to read Brian Mathato's question about his VW Chico that stalled while he was driving it because I have a similar, but slightly different, problem with a BMW 330 (2000 model) which has a fuel-injected engine.

I WAS interested to read Brian Mathato's question about his VW Chico that stalled while he was driving it because I have a similar, but slightly different, problem with a BMW 330 (2000 model) which has a fuel-injected engine.

My BMW sometimes stalls when I am driving, usually after doing about 50km in hot, sunny weather. When the car has cooled down for 20 to 30 minutes the engine starts again and I can continue my journey.

Amazingly the car does not have this problem at night, early in the morning or in cloudy conditions.

When BMW could not help me in December one mechanic suggested that I replace the camshaft position sensor, but the problem did not go away. He then suggested that I should replace the crank sensor, but I challenged this.

He also advised that the petrol pump and filter needed to be replaced, but I doubted that, because the car drives well when it is cool. I booked my car in to be checked by BMW Club Motors. A co-worker of mine faces a similar problem and warned me that the engine might have been affected. I would like to hear your viewTSHIDINO NDOU

TSHIDINO, this is indeed a baffling problem. Many years ago, when carburettors were still the norm, a so-called vapour lock sometimes developed in the fuel line on a very hot day, leading to the symptoms that you describe.

But this problem was already solved during late carburettor era. It should never happen with a fuel-injected engine.

I spoke to an experienced technician and he suggested two possible causes: "dry" solder joints on the fuel pump relay, or dry joints on the immobiliser module if it is an after-market immobiliser. (A factory-fitted immobiliser would normally be integrated into the car's electronic control unit).

He has had cases of such dry joints acting up at high temperatures and causing the symptoms you mention. I suggest you ask an auto-electrician to check the connections on the fuel pump relay and immobiliser module (if applicable) for dry joints as a first step.

You could instruct the workshop, where your car is booked in, to have this done and then consult you before proceeding.

Without wishing to destroy a relationship of mutual trust that you might have with the workshop, I would advise against giving a workshop (any workshop anywhere) a free hand to cure a problem like this.

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