I am getting chipped 28 to run my GSR, so if i wanted to upgrade to OBD2 prelude injectors, would I have to do anything to make them work correctly?

 

Do you have an OBd2 injector harness or OBD1 injector harness? If you use the OBd1 injector harness/clips, they are different then the OBd2 injectors.

jason

 

I believe that the prelude injectors require a resistor pack to function correctly. Might want to do a little more research before installing.

 

The car is originally OBD2a.
I am getting a chipped p28 w/ an OBD2 to OBD1 harness.
I want to use OBD2 prelude injectors, i know they plug right into the stock OBD2 injector harnesses on GSRs, but my question is since i'll be using an ODB1 ECU, would i have to change the harnesses for the injectors

 

I think this is what your asking. Why or how can I run a OBDII injectors(Hi impedance) injectors on a OBDI ECU ?

The reason you can use the OBDII prelude Injectors with your P28 ECU because the OBDII Prelude injectors are Hi resistance(12-13 ohm) and only require 1A-.9A to open and stay open. Both the OBDII and OBDI ECU output about the same amount of amps when controlling an injector. So basically the higher resistance from the injector compensates for the need of the resistor box.

Which is the same reason why you cannot use peak and hold injectors on a OBDII without a resistor box because the OBDII ECU does not output enough amps to snap open the peak and hold injectors without the additional resistance.


Here's an excerpt from TWM that can also help you out. http://www.twminduction.com/EFI/EFIInjectors.html

Injector resistance is an important consideration when matching ECUs to injectors. Injectors are manufactured as low resistance or high resistance. Low resistance injectors typically measure in the 2 to 5 ohm range, high resistance being 12 to 16 ohms. It is important to match injectors with the injector drivers in the ECU being used. Generally speaking, original equipment ECUs are equipped with saturated drivers which drive high resistance injectors. Aftermarket ECUs are equipped with drivers for peak and hold injectors which are low resistance. Some aftermarket ECUs will drive both types of injector: It should be mentioned, however that injectors for saturated drivers do have a slower response time than those for peak and hold. Most peak and hold drivers will drive both high and low resistance injectors but, under no circumstances, should peak and hold injectors be driven with saturated drivers.

To calculate the current requirements of an injector use Ohms law and divide the system voltage by the resistance. Therefore, in the case of a high resistance injector of 12 ohms operating on a 12V system, 12/12 = 1 amp. In the case of a low resistance injector operating on a 12V system we have 12/2= 6 amps. Observe that the current requirement for a peak and hold injector during the opening phase of operation is much higher than the saturated type, the current peak being used to "snap" the injector open. Drivers for peak and hold injectors are typically limited to 4 amps or 2 amps for opening and 1 amp or .5 amps respectively, for the hold period.

 

TRuST, thank you very much, you answered alot of my questions

 

No problem