James, You are probably correct on the injectors and the mis firing. I do have a cleaning system set up now on the site to clean them if new ones aren't in the budget. The other part of the problem could be the system pressure or the control pressure. In other words, are the injectors getting enough pressure to open them properly. John Hervey www.specialTauto.com . << Hi all, I am still having an annoying misfire, I am pretty sure it down to an injector that is passed it's sell by date, as it is not spraying very nicely. To my knowledge the spray pattern on a mechanical injection system is more crucial than on an EFI system because the valves are not always open at the point of injection. I am fairly sure the misfire is fuel related for the following reasons: 1) My timing light suggests that all plugs are sparking 2) All plugs are less then 8 months old. 3) 2 of the injectors are new, 4 are 2nd user but appeared to be clean and ok when 1st installed approx. 10 months ago, and the engine has run fine until recently. 4) All of my HT leads are new as well as the cap and rotor arm. Anyway my question is really why are the injectors getting blocked?, have I just been unlucky? I have a new fuel pump, clean tank, and a filter on the fuel pickup and had the main fuel filter change about 10 months ago. Any ideas? James RG >>