Injector Current & Peak Hold Ratio

[rickytcf]

Hi,
How do I setup the following properly.
1) Injector Current
2) Peak Hold Ratio

I have Mitsubishi stock injectors 550cc, 3 ohms.

Injector current should be set as 14V/3ohms = 4.66 amp?
How should I calculate the peak hold ratio?

Example : RC Injectors have 4ohm peak and hold at 1.5ohm, what is the for -->
1) Injector Current
2) Peak Hold ratio

Regards
Ricky

[MarkMc]

The peak hold ratio will always be 4 for normal automotive injecotrs. The current depends on the injector and we would usually test it with an osciloscope and a current clamp.

Do you have the standard injector circuit resistor still in place in the car? If so the current setting is 0 for saturated drive. If you have removed it you will need to set the current correctly. Can you give me the part number of the injector?

[rickytcf]

I do not have the injector circuit resistor. It has been removed.
I am using stock Mitsubishi EVO 3 injectors.

[MarkMc]

Not sure exactly what the current setting is without testing the injector, as a simple "get out of jail free" you can use one of the settings in the help screen for an injector with the same resistance.

Another way is to keep going up in injector current until you get a "peak" error and then drop it back a couple of points. The current setting is just for the ECU to know when to change from peak to hold current.

[ElectronSpeed]

MarkMc:>The peak hold ratio will always be 4 for normal automotive injecotrs. The current depends on the injector and we would usually test it with an osciloscope and a current clamp.

I can perform the test if you can give us a clue about what we are looking for on the oscilloscope.

FWIW, I am working with a Bosch 0 280 150 400 with a resistance of about 2.5 ohms.

Using the "free" answer of choosing a similar resistance from the M800 help files implies that I would want something on the order of 2-2.5 amps (peak?) and hold at 0.5 to 0.6 amps?

These numbers are obviously well below what the steady state current would be for a 2.5 ohm device.

I am running these with an M150.

thanks,

Eric Schieb