Down on power
I have a 2005 Ford Focus 1.8 turbodiesel that’s down on power. The only fault code indicates the glow plugs are not working.
Also, are there any articles relating to fuel system and turbo boost control? Peter Hendron
In 2014, CM had a Focus 1.8 TDCI project that was introduced in the January issue and ran until June 2014. Work covered in the series included changing the timing belt and filters, sorting the suspension and brakes, checking the glow plugs and bodywork concerns. In 2013, the May issue covered electronic diagnostics on a Focus 1.6 TDCI.
Regarding your low power, with no code showing it is difficult to correctly diagnose the problem. The fault may be in one of four main areas: the fuel system, the electronic control, the air inlet or the exhaust system.
If the low power is accompanied by smoke from the exhaust, this would suggest a fuelling or air mix problem. A blocked exhaust can cause excessive back pressure, which will limit the power output of the engine. With the air inlet system, one of the common failures on the 1.8 turbodiesel engine is the intercooler hoses – the rubber hoses can perish between the intercooler and turbo pipes, so check these thoroughly for any small holes or splits, and that the securing clips are tight.
With the electronic control system, the data I have suggests that your Focus is fitted with a mass air flow (MAF) sensor. This is a good candidate for the symptoms you have and wouldn’t leave a fault code in the system. By unplugging the sensor and driving the vehicle, you may find a short term return of power. Being unplugged, the sensor should also leave a code in the system which will then need to be erased. If power is returned with the sensor unplugged, you can either try cleaning the sensor wire using an isopropyl alcohol or dedicated MAF cleaner or else replace the unit. If you do try to clean the sensor, be very gentle with it and ensure that it is fully dry before starting the vehicle.
I do find Ford systems particularly difficult to access with generic equipment. If none of the previous suggestions bring the problem to light, it may be worth getting the codes read with a dedicated Ford diagnostic system.