xe poor running

[soup1]

friend has an xe running poorly
with slight throttle it is holdin back a bit and is throwing out a lot of black smoke
have tried cts and airflow meter but no different
car drove perfectly before being parked up for 4 weeks
any suggestions?

ps it is also down in power as well

[gmopeldealersport]

could possibly be coolant temp senser these make the engine run really rich .its located next to thermostat housing blue sensor (usally) also check the wires on connecter somtimes there broken .they cost about £10.had a few xes with this problem.