Setting unknown injectors

If the linearization table for injectors is not known and can't be found, is it better to throw in a guess and work it out by trial/error or better to get some different injectors for which you can get the data?

Andre mentions that it doesn't really matter and "back in the day" this was never even an option. But now with more complex closed loop control, compensation tables, etc, is it something that's better done with the right specs?

Having quality data for your injectors is a valid reason to pay a bit more. If you have more time than money, you could set up your own test rig to determine the injector characterization.

If you know the spec's within 10%, then errors for a 10% trim would be less than 1%. So as long as the guesses are well founded (injector is a direct replacement for another injector that you do have the specs for), or you've done at least the simplest test to verify overall flow rate -- you should be quite OK.

Thanks David.

Temptation is to go for known new injectors and be done with it.

Having said that, I have played with the thought of setting up a primitive injector cleaning bench. Wouldn't take much more to throw a voltage regulator in with the mix

Get a benchtop power supply. Very handy for all sorts of testing outside of the car.

https://www.ebay.co.uk/b/Bench-Power-Supply/bn_7024884866