IVAN93EG

my friend just purchased a obd2 gsr (dont know year) for his 94 dx hatch. he has no ecu for it. we want to do the swap ourselves and i searched and found that we need to change 2 wires on the dizzy. still dont quite understand o2 wireing. pretty sure his car is prewired for vtec.(i think). does he need an ecu from an obd1 or 2? every thread i found on this subject was for a vx. is it all the same? the install seems to be the easy part but the wiring kinda scares the **** out of me. i know all about the search button and i've been searching this for 2 days with no answers. if you could direct me to a useful thread it would help tons. this is our first swap and you guys are the only ones i would trust for the facts. thanx

boosted92hatch

you definatly want the obd1 ecu. its the p72. to run obd2 you will have tons of wireing including a 2nd oxygen sensor. i have a 92 hatch cx and i put a y8 in it recently and i am ready to drop a gsr in there that i just picked up. i ran the obd1 ecu on the obd2 motor just removed the sensor down near the pulley. wont need it. also the obd2 ecu wont even plug into your car. the injectors will have to be changed. because the obd2 plugs are different. there the same 240 cc's anyway. then yes the vtec wires are already ran out to the engine bay. they stop at the plug just next to the strut tower you will have to get a spare plug and depin a few pigtails and use them as leads to come out the other side. your car should already be eqipped with a 4 wire 02 sensor. so the only wires u need are for vtec. as for the third wire i just tapped that back into the harness were the haynes manual i was reading from said it would be had the car been a ex with vtec already there. hope this helps u some

IVAN93EG

is the p72 an ex ecu? do all ecu's come with vtec capabillities? thanks for not leaving me hanging

IVAN93EG

sorry for the stupid question. i found the p72 in the faq section as a obd1grs ecu. i'm not trying to get spoon fed the info. so the way i see it change injecters,change the dizzy wires, run vtec wires and ecu and what else. do we need to change the voltage regulators in the alternators.


Modified by IVAN93EG at 9:34 PM 5/27/2006


Modified by IVAN93EG at 9:59 PM 5/27/2006

NVturbo

To make things more simple...two options:
1. get a OBD I P28 (EX/Si) ecu and socket/chip to GSR specs [you will not have KNOCK sensor or secondary throttle body]
2. get a OBD I P72 (GSR) ecu

If the harness of the new motor is still intact...all you have to do is run your VTEC wires and knock sensor (if P72 ecu is used) from the ECU into the engine bay. You can actually insert the wires into your car side of the plugs (that's if you have extra pinned wires available).