what years and models used low and high impedence injectors? also does anyone know how a series 4 handles the secondary injectors? does it cut all injectors to 50% duty cycle? is that true?

 

bump

 

Search, its all been covered a few times.

 

secondary injectors come on at 3800 Rpms, or under heavy loads. If the primary injectors are staying open for 10ms when the secondaries come on, then all 4 go to 5ms. Double the number of injectors at half the open duration, and you get the same amount of fuel. (So long as the secondaries are the same size as the primaries).

For injectors, they went from high impedence to low impedence some time in 87. Have to do a search for injector impedence to get more specific info.