raidacaipo

I heard that a resistor box is not needed if your using any other ecu besides a prelude. This may include using a p72 ecu for a h22a swap in a civic. Am I correct or am I wrong?

joelmatt89

if your ecu is obd1 and your injectors are obdII you need a resistor box, if your not sure about your injectors check the resistance if it is 2-3 ohms you don't need a resistor box, to directly answer your question if you have an h22a with a p72 yes you will need a resistor box

raidacaipo

So low impedance injectors that peak and hold will need a resistor box? what about aftermarket injectors like RC that are high impedence? will I still need a resistor box for those?

raidacaipo

my h22 is a 96 therefore I believe its obd2 but it has obd1 style injector plugs. Kinda weird huh? I believe the transition to obd2 started in 1996 correct? and my distributor is an obd1 internal coil. So I still would need a resistor box eh? what if I run high impedance injectors?

CivicSpoon

The '96 JDM H22A's are still OBD1. If you run high impedance injectors (saturated), as well as continue using the P72, then you don't need a resistor box.

raidacaipo

I see. Well if it makes any difference my car is a 96-00 civic ek hatch. Here's the book where I got my info from and where the confusion takes place:

92-95 civics - "An injector resistor box must be mounted to the chassis and wired into place in order for the saturated Prelude injectors to function properly. The purpose of the resistor box is to reduce the amount of electrical load on the drivers inside the ECU. Failure to wire this baby up will eventually result in a burned-up computer" Aaron Bonk - Honda engine swaps

96-00 civics- "Other modifications include the addition of a fuel injector resistor box. Resistor boxes such as these may be found on older OBD 0 Civic and Integras, as well as most Preludes. A fuel injector resistor box is only necessary when using a Prelude computer." - Aaron Bonk - Honda engine swaps

raidacaipo

bump

joelmatt89

why did you bump it what are you confused about it seems like they answered your question

TheRappist

lol looks like your book is wrong. Should say PEAK and HOLD injectors.

raidacaipo

because 2 heads are always better than 1.

raidacaipo

yeah your all right.. peak and hold injectors with 2-3 low impedance always require a resistor box. Now I know that but I wasn't quiet sure because of this stupid book Ive been reading. So I have 2 choices now.. either get high impedance saturated injectors and I dont have to use a resistor box or get a resistor box if I plan on using the stock jdm h22a obd1 injectors.

joelmatt89

well resistor box will be cheaper by a few 100, although if you want to save more money and you don't want a resistor box under your hood you could just get 4 ten ohm in line resistors from radio shack, a lot of people think that you have to get the little oem box deal but those will do the same thing and you could tuck them pretty easy

raidacaipo

really?? wow thanks for the tip.. btw what size cc are the stock h22 obd1 injectors??

raidacaipo

Hey I just realized something. My h22a engine is a 96 model. Therefore it should be obd2 am I correct? So it means that my fuel injectors are obd2 high impedance injectors meaning that I dont need a resistor box. Is this correct?

sicc22

go buy a multimeter from radio shack and find out the resistance. If you have to question what kind of injectors you have its better to be safe then sorry.

D16SiHatch

this information i found some time ago seems pertinent and maybe will help others clear up some discrepancies.





So in a nutshell. if you are using obd0 peak/hold injectors then you will need a resistor box. if you are using obd1/2 saturated injectors then you do not need a res. box.

raidacaipo

wow really good info.. thank you so much.. its very clear now