How can one tell the injectors need more than Techron? The trim readouts getting wacky?
What can one do to not have to send them to you? Use top tier gas?
What about diesel injectors? Or a different ball game?
It depends on a lot of things, if its a new vehicle or new injectors than top tier should take care of it if it is a daily driver. Certain conditions are problematic one of them being storage which is common with marine injectors.
Fuel trims irregularities, codes, misfires, rough running, etc can all be caused by dirty injectors, some scan tools can test individual injectors on some vehicles (I don't know every car or every tool but it wont be a cheap one).
Ohms testing is in general of little value except for diagnosing a open or short, testing the actual power consumption running is a better test this can be done in a machine like I use off the engine or with a scope on the engine but that will not tell you how it is flowing or how its spray pattern is.
Running a product like Techron, Redline SI-1 or other PEA cleaner is a good idea every 3-5K, if varnish is an issue a solvent based product like Berrymans Chemtool works best and is best for carbs especially ones on OPE, a splash in every tank in my experience will keep a clean carb clean indefinitely.
Somethings you can do nothing about is issues with DI, some are prone to filter burn out which drops particles down in the injector clogging it to various degrees sometimes badly and carbon clogging, another issue is the burn out of the teflon or graphite sealing ring.
These must be professionally serviced.
