This is my first technical thread so please feel free to give feedback.
Driving to work one night, the car (GT 1.9 diesel) lost power, started to vibrate and the engine light came. The diesel level needle on the instrument cluster also went mad, oscillating between full tank and empty.
Connecting it up to the computer, there was an error reported on injector 3. So I replaced injector 3 with a new one (ouch) and reset the ECU. That solved the problem (great!) but a day later the same thing happened. Seemed like the injector blew again! Being hopeful that I wouldn't have to buy another injector, I reset the ECU again and the problem magically went away. Following this, the problem would come and go.
I ended up checking if the ECU was broken and it wasn't. Took a multimeter to all the wires from the ECU to the injector and they were fine. FRUSTRATION.
Eventually I accidentally bumped the plastic socket that connects the wires to the injector (don't know what its called, plastic clip I guess) while the engine was running and the problem stopped.
Turns out that the metal contacts in the 'plastic clip' were not making a good electrical connection with the pins on the injector. I squashed the little contacts in the plastic clip a little so they would make a better electrical connection and voila, everything worked perfectly. The problem was temperamental because any movement of the injector wires (like when accelerating) would effectively disconnect the injector.
An expensive lesson and now I'm sitting with a spare working injector that I don't need. But if this thread can help even one person from making the same mistake, i'll be happy