Are the 85'GSE-SE Fuel Injectors 680 cc drop in replacements for the secondaries in a 91 Turbo? Or is there something else I must do?

 

I know they will fit the fuel rail properly and be a direct drop in but Im not sure if they are low or high impedence. If they are high then you are good to go.

 

they are low

 

So if they are low, then it can't be done?

 

Not 100% here, but I beleive they are a low impedance... and your car is high impedence.
You'll need (I THINK!) resistors, or the resistor pack from a junkyard 86 rx7.
Not sure about the plugs either, might need to pick up some injector plugs from the junkyard and just put them on. Either way, it's not a big job at all. Very easy.

 

The GSL-SE injectors are low impedance, and your car is expecting high impedance. To fix this, put a 10 ohm 10 watt resistor in series with each injector connector. Doesn't matter which wire you put it on.

Don't use the resistor pack because that will also effect your primaries.