From OAP pete.....problem is Lead free petrol turns to a Red/Pink.ish gunge in 1 year ive found as recent help given to owners, The injectors themselves have a valve in them...so the "gunge" ether stops them spraying or makes them dribble, You can clean them on the car...First is to Pump all Fuel from Tank..the best way is to undo the Pipe from the 5th Electric injector...pop in suitable canister...unplug injection relay...bridge terminal 30 with 87..no ignition needed, pump will run on main line pressure now 80 / 90 psi, once you hear the pump struggle re - allmost empty...unplug bridge so as not to overheat pump..as they use the fuel too cool, as the pump allways runs at 80 / 90 psi whilst driving...of course injectors dont get this pressure, depends on throtle used. now remove all injectors with there pipes connected...insert in suitable Jars, you now need to get plenty of Fuel injector cleaner, it can be purchased in 5ltr can...instead of the small bottles...pour all in tank...refit pipe to 5th injector...you can now use the pump to clean injectors...bridge relay again...any drips from injectors is not correct...but push down the metering Flap...High pressure will open the injectors...cleaning will take place....you can observe spray...keep the action going...full pressure 80/90 psi will be obtained on full push on flap, keep this up working flap. Have some injectors go a better spray...now to do the very important "leak test" stop pump...wipe all 4 injectors clean...rebridge pump...now observe for any Drips / dampness on nozels..the pressure will be with this test 30 / 38 psi....there must be Dry injectors, hopefully will be ok...also the cleaning will have also cleaned the metering head...any injector that does not spray or leaks is damaged...or you can try another clean run, the cleaner of course is returned to Tank...you can remove as above...and fill with good petrol...expensive on cleaner i know, but i feel worth a try... hope of help. Peter [ p/s...remember as jars fill ....listen to pump not running out...i put the cleaner when full back in Tank for another run, as cleaner returns to Fuel filter then metering unit an injectors ]