Hi John,
The constant 12v to the injectors may be normal. It is on a Bosch system. The injectors are activated by earthing them.
The simplest method of seeing if the injectors are working is to listen to one through a stethoscope whilst the engine is cranking. You should hear them ticking. On a Pug or Cit the ticking is very pronounced at idle and it sounds like tappets needing adjustment.
Otherwise, use an oscilloscope across them or use an analogue voltmeter. The needle will measure the mean voltage across them and you may even see the needle flicking as they fire.
Even if you have sparks and injection, the engine may still refuse to start as the air:fuel ratio must be pretty nigh exact to allow a start. If it is way out it will not even fire.
The usual suspect on the F*** is the mass air sensor just downwind of the air-filter. It's a hot-wire one and a bit delicate.
Fuel pressure is an unlikely cause unless the regulator has gone completely and the fuel pressure is very low. You can do a rough test by letting the pump run, shut off and then carefully poke the schrader valve on the fuel rail (under a blue cap) whilst covering it with a rag and judging roughly the pressure released. You can even put a dial-type tyre gauge on it. Look for 2.5 bars or so.
The sparks may be a red herring. The coils are of the double-ended wasted spark type so one spark will be positive and the other negative. I'd expect them to look different because of this.
Hope that helps a little. SWMBO had a Fiesta as her first driving school car and then passed it on to our eldest son. I got to know F***s very well over the years as Dad also ran them until I converted him. SWMBO now rus a C3 as her tuition car
1.8 Petrol, rail injection
