Low impedance injectors with resistor pack

[GeordieSteve]

Bit of an urgent one chaps. What would be the result of running a resistor pack with low impedance injectors in a J spec, or not running a resistor pack with high impedance injectors? Would there be some very noticible problems?

[Ric]

they wouldnt work?

[GeordieSteve]

Yep but I'm looking for a little more detail as in what problems I would face. I've currently got problems after a resistor pack was installed

[gzaerojon]

Bit of an urgent one chaps. What would be the result of running a resistor pack with low impedance injectors in a J spec, or not running a resistor pack with high impedance injectors? Would there be some very noticible problems?



surely it's the same thing?? the stock injectors are high impedance anyway, so the only reason for fitting a resistor pack is to enable you to run low impedance injectors

[GeordieSteve]

Scruttocks... other way round then

[Armin]

is there a plugin on the japspec supra for a resistorpack or will you have to solder in i on the harness?

[jagman]

The simple answer is yes you would have problems.
Impedence is the term used for electrical resistance (ohms)
but in an AC circuit .
in a DC circuit resistance is used.
dont ask why impedence is used and its a DC circuit cos I will be here all day trying to explain!! but it has to do with the supply being pulsed ,one pulse opens the injector and then it closes allowing fuel through the injector.
the time the injector takes to open and close is critical and must remain constant so as to allow a precise amount of fuel each time
this allows the ECU to effectively control the amount of fuel by the amount of pulses it sends to the injectors.
matching the injector resistance (impedence) to the ECU ensures that this time value is kept constant,and coupled with constant fuel pressure gives perfect mixture control.
mismatching injectors by wrong resistances or poor connections,or high resistances totaly fooks up your mixture.
the ecu even has a feed from the electrical power supply to measure the supply voltage and will alter its pulses to suit,keeping the fuelling constant despite changing battery voltages.
Refer to first line -yes

[GeordieSteve]

We've found the issue now anyway :( 1 fooked MAPII ECU

Much appreciated Jagman!