I am planning to investigate further into the cause of the long crank times on my SIII (warm or cold), and I see from the wiring diagram that there are resistors in the power side of the injector circuit



1987 SIII Fuel Injector partial wiring

I wonder if there are any long term problems with these resistors such as burning out etc. What should the resistance be across the pins of the connector. Is there any maintenance to do on these? Should they be replaced periodically or they last indefinitely. Are they located on the right side fender wall of the engine? Is it best to get at them from above or below?

 

There have never been any maintenance instructions for these resistances, although checking the plug connections for corrosion is an obvious move. They are part of the return line from the injectors to the ECU, one resistor per injector. The way the fuel injection system works, is that there is a constant voltage applied to each injector, and it is fired by the ECU earthing them all together for a variable length of time thus varying the fuel injected. The injectors are fired all together twice per engine revolution. So if a resistor fails open circuit, that injector will not fire. What the effect of increased resistance would be due to contact corrosion, I'm not sure.