obd1 jdm b18c swap in 99 hx??

[projekteg]

here's the set up in question, obd1 jdm b18c (gsr) in a 99 hx coupe, he used the stock hx harness and also converted the car to manual at the same time, converted to obd1, using a variety of ecu's (p28, obd2 hx ecu, and p72), i guess whichever one works best that day ok, here's the situation, a guy on a local board made a post about getting an ect cel with his jdm b18c in a 99 hx. i ask him for a brief summary of his set up and find out he's running an obd2 to obd1 conversion with a stock p28 with the b18c, i ask why and he says that the p72 was auto. he was getting the ect cel with the p28 and he said he ran the obd2 hx ecu and got a lot of codes also but the car ran better with the hx ecu???. i was amazed that he was running the b18 with these computers and i offered to convert his p72 to a manual ecu. i did that, thinking this would solve all his problems and make the car run great, i met up with him and plugged it in. then we were getting codes 6, 14, 21, 41. so i looked at his engine and he had the coolant sensor and the sensor underneath the vtec solenoid backwards, his iacv wasn't even plugged in (but he didn't even get that code with the other ecu's??). i believe the vtec solenoid code is because he has a bad solenoid, i tested the voltage and it jumped all over the place, then i tested mine on my b16 and it was at like steady 19 vdc, so i assume his solenoid is bad, ok, that's one cel out of the way. he says that he used the primary o2 sensor that was in the hx manifold, i found the pin outs for the o2 sensor, but the colors on his plug didn't match the ones in the diagram i found, i'm assuming b/c he has an obd2 harness and the diagram was for obd1. also shouldn't the hx have had a 2 pin iacv plug? the colors on (what i believe to be) his iacv plug don't match the ones ones on my 00 si iacv plug?? i'm really stumped and would love to help this guy out, but wiring isn't my strong point, any help, advice, solutions, feedback, is greatly appreciated! btw, i just found this site while searching ht and there seems to be a lot of great info. here, i'll be visiting frequently, i'm a mod on hmt and that's where i spend most of my time, but great site! tia

 

[projekteg]

ok, well after reading around on the site for about an hour or two, i may have found all my answers. i don't know what i was thinking about the iacv, his car use to be auto, so i need to convert it to a 2 wire iacv (i was wonering why the wires on the plug by his iacv weren't the same color as mine). and after looking at the 'article of the month', i see that the author was throwing almost the exact same set of codes and it was b/c the canon plug wasn't plugged in, i checked almost everthing on this guys car except for the factory connections, i'll have to check that out, but he's not getting code 15, like the author of that article was, just all of the other ones?? i hope this is the problem, that would be awesome. any other feedback is appreciated though, and i'll update the thread if i find out that was the problem.

 

[posol]

do not even consider running the hx ecu on a gsr motor. it will run it dangerously lean and with horrible ignition maps.

First, make sure your parts are in order.

your stock hx harness.

obd2b->1 conversion harness.
ECU: chipped p28, obd1 p72, or obd1 p30

obd1-2 IAB wire switch.
you need to do the oppoiste of what is listed here: https://hondaswap.com/forums/index.php?showtopic=29813

5-wire to 4-wire o2 sensor conversion
https://hondaswap.com/forums/index.php?showtopic=14242
that's for an obd1 vx, so you're wires in the bay may be slightly different. i'm not sure what.

add wiring for IAB secondary manifold butterflies, knock sensor (if your car doesn't have it already)

that should be it.

 

[projekteg]

yeah, when he told me he was running the stock hx ecu, i freaked out and told him not to drive it like that b/c he was starving it for fuel, same with the stock p28, that's why i converted his p72 to a manual ecu (he bought an auto swap) for him b/c it was easier than chipping the p28 for him and the p28 won't run the iab's either that i know of. i know how to re pin the iacv, it just didn't cross my mind b/c his car is manual now, so i didn't think of his original harness having the 3 pin iacv b/c it 'was' auto. as far as the other codes, i'm really hoping it was just the plug by the shock tower since i saw the same set of codes from 'the article of the month' and the author said he forgot to plug the canon plug back in. if that's not it, i'm stumped on codes 6, 21, and 41. the hx has 4 wire o2 already, so there should be no wiring problems for that, and he said his o2 sensor is fairly new....