Why does my Focus keeping cutting out?

I am reaching the end of my tether with my 2003 Ford Focus. It started at the beginning of the year when it started cutting out. The breakdown guy diagnosed the battery, so I bought a new one and it seemed to fix the problem for a while.

However, the car now cuts out when it rains and refuses to start. I’ve been to two different garages, who cannot diagnose the fault, with both saying it might be something to do with the key or immobiliser. Following their advice, I have tried the spare key and also spent £100 on a car locksmith and still nothing. Can you help?

Asked on 1 September 2014 by Diziblond

Answered by Honest John
You mention the pollen filter. It could be that the drains to the bulkhead vent well are blocked, leaving rainwater nowhere to go except into the car where it can damage some of the electrics, but you'd know about that because you'd get wet feet.

The most common cause of cars not starting in the wet is deteriorated HT lead insulation or a problem with the insulation of the coil packs. Another problem specific to the Focus 1.6 petrol engine is that the gulley on top of the engine in which the spark plugs sit is prone to collecting condensation water, causing starting problems and eventually rotting out a core plug. So have a look and try drying that out.
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