Fiesta fault

My 1998 Fiesta Zetec only has 33k miles but has started dying while driving. It randomly starts and then doesn't start, so can't be trusted. I recently replaced the fuel pump, fuel filter and air filter. This car had previously only done 500 miles a year for the last 3 years so it's being driven more since I bought it a couple of months ago. The garage that has maintained it for the last 10+ years does not know what is wrong with it. They replaced the relay switch but then it died on them, too. Any clues?
Filth, contaminants, rust and emulsified fuel in the fuel tank from its long periods of sitting around. Have the entire fuel system drained and professionally cleaned out.
Answered by Honest John on

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