Dan, what is the condition of the up stream 02 sensor? This could very well be the issue if the ecm is seeing a 0v signal from the sensor, so in return the ecm thinks the engine is running lean. Do you have access to a scanner? I'd bet that your ecm is in open loop status. Lets start here and see if the 02 sensor is the problem.
'I know where the 'zetec' kicks in....'