Many of the older injectors will need to be "back flushed"
Not all older MFI and CIS fuel injectors are "restorable." Some are just plain worn out. If the tip is worn out or damaged there is nothing you can do to repair that. There are no replacement parts available for Bosch mechanical gas fuel injectors. You can not replace the tip. The fuel injector is sealed up tight during the manufacturing process.
But when a fuel injector won't fire at the right pressure or may spray sporatically, it might not be a worn out tip. There is something inside the fuel injector that could be causing the problem and this can only be addressed by forcing cleaner "backwards" through the fuel injector.
For the past 6 months Kent has been refining a process that will allow you to do just that on your workbench using his bench mount tester and fume capture bottle.
Watch Part 1 as he shows the why and how of this process when dealing with C.I.S. fuel injectors. Part 2 covers the same procedure with early mechanical fuel injectors of the 1960's ( MFI ). - Part 3 COMING SOON..