In honesty as above, when they're worn, they're worn, no amount of cleaning will fix it. The early CRI1 injectors don't last very well and just because the cylinder correction quantities and leak-back between cylinders are acceptable, doesn't mean they've not got worn internals etc. Remember that the per cylinder correction quantities are only based upon the crank acceleration per cylinder that is increasing the overall engine speed more than the others, i.e. if all injectors were worn evenly and injecting too much - the ECU cannot correct for this because the control logic does not have a calibration of engine speed to injected quantity since this changes hugely depending on temperature and wear etc, it's highly variable, combined with the fact that the pilot quantity is not corrected per cylinder. Only later management systems with Lambda feedback (FMMA) can really compensate for the injectors being out of calibration.
New nozzles and calibration will make them absolutely perfect again, but as is predictable, it's not cheap. You can probably pick up some tested injectors for not a huge amount.
New nozzles and calibration will make them absolutely perfect again, but as is predictable, it's not cheap. You can probably pick up some tested injectors for not a huge amount.
