Obd1 to 2 conversion
02-13-2017, 02:04 PM
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Obd1 to 2 conversion
Hey, I have a bit of a problem. I bought my 97 Prelude and it has obd1 injector wiring and I was wondering if anyone could tell me how to take out the resistor box, and where exactly does the injector wiring connect to If someone can, that be great!
02-21-2017, 11:37 AM
#3
Re: Obd1 to 2 conversion
An OBDII 97 Prelude shouldnt have an OBDI engine harness or even OBDI "injector wiring" by means of a modified OBDII harness. It shouldnt have a resistor box either and it shouldnt have Peak and Hold injectors, they should be the Saturated type.
Check to see what ECU your running, whether its an OBDI or OBDII ecu as well as if its a JDM or USDM ecu.
Also check to see what engine you have. There should be a stamp on your engine below the upper coolant hose with an "H22" followed by a letter and then a #. There may also be an "H23" followed by a letter and #, see what it says.
It is possible that your car has had a swap performed and is running a JDM H22A engine which is most likely an OBDI motor with a P13 ecu. It would also most likely be running 345cc Peak and Hold (Low Impedance) injectors. WITH an injector resistor box.
97 USDM Preludes have an H22A engine that is OBDII and run a P5M ecu as well as 290cc Saturated (High Impedance) injectors that do not run an injector box.
USDM OBDI H22A Prelude motors run either 310,330 or 340cc injectors of the Peak and Hold (Low Impedance) type, WITH a resistor box.
Note
The flowrate spec is hard to get a good solid answer on, there are all kinds of answers as to the flowrate of injectors but in either case you dont really need to know to solve your problem)
You will need to determine if your injector wiring consists of an entire OBDI engine harness or a modified OBDII harness.
If you do have an injector resistor box and are running Peak and Hold injectors, the injectors are supplied 12v power via the resistor box, this is a constant 12v as the injectors are operated by switching on and off the ground, not the power. The box is typically located near the brake master cyl/booster under the hood. The ground for the injectors is supplied by the ecu and when applied results in a closed injector. The switched grounds are 4 different colored wires that run from the injectors to the ecu as part of the engine harness.
Hope you or others can benifit from the post, let me know if I need to be corrected.
Check to see what ECU your running, whether its an OBDI or OBDII ecu as well as if its a JDM or USDM ecu.
Also check to see what engine you have. There should be a stamp on your engine below the upper coolant hose with an "H22" followed by a letter and then a #. There may also be an "H23" followed by a letter and #, see what it says.
It is possible that your car has had a swap performed and is running a JDM H22A engine which is most likely an OBDI motor with a P13 ecu. It would also most likely be running 345cc Peak and Hold (Low Impedance) injectors. WITH an injector resistor box.
97 USDM Preludes have an H22A engine that is OBDII and run a P5M ecu as well as 290cc Saturated (High Impedance) injectors that do not run an injector box.
USDM OBDI H22A Prelude motors run either 310,330 or 340cc injectors of the Peak and Hold (Low Impedance) type, WITH a resistor box.
Note
The flowrate spec is hard to get a good solid answer on, there are all kinds of answers as to the flowrate of injectors but in either case you dont really need to know to solve your problem)You will need to determine if your injector wiring consists of an entire OBDI engine harness or a modified OBDII harness.
If you do have an injector resistor box and are running Peak and Hold injectors, the injectors are supplied 12v power via the resistor box, this is a constant 12v as the injectors are operated by switching on and off the ground, not the power. The box is typically located near the brake master cyl/booster under the hood. The ground for the injectors is supplied by the ecu and when applied results in a closed injector. The switched grounds are 4 different colored wires that run from the injectors to the ecu as part of the engine harness.
Hope you or others can benifit from the post, let me know if I need to be corrected.
Last edited by Accordian47; 02-21-2017 at 12:11 PM.
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