Starts but Runs Poorly

Petrol engine Starts but runs poorly

Commonly caused by incorrect parameters supplied to the engine ECU by the MAF or water temperature sensor.  The ECU then over -or under- supplies the injectors.

About once a year it is beneficial to use a bottle of injector cleaner to clean out the fuel system.

  1. Can be caused by the MAP sensor  1.4 engine here      1.6 engine here 
  2. Remove the air filter and check it isn't restricting air flow
  3. Clean out the butterfly and air intake area with carburettor cleaner
  4. Check the water temperature sender  1.6 engine here 
  5. Check the plugs - Peugeot only change every 40,000 miles by which time the gaps can have opened up to over 50thou.   1.4 engine here     1.6 engine here 

A nice trick is to unplug the MAF.  The ECU then changes into a low-power failsafe state.  If the cause is one of the sensors, the problem should then be gone.  However be aware that if the problem disappears when you disconnect the MAF, the cause can still be any sensor.