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OBD1 B16A SWAP

4K views 20 replies 2 participants last post by  crxvtec91 
#1 ·
Alright I know this is covered all over the internet, but for my particular application I couldn't find much. Car is a 88crx dx. Its kinda of turned into a little mess. Heres my setup currently obd1 b16a, p28 chipped from phearable, obd1 dizzy, obx 4 wire o2 sensor, obd0 to obd1 ecu jumper harness, obd0 to obd1 dizzy jumper harness. I bought the car with a stock dx d15b2 engine and swapped in what i thought to be a obd0 b16a. So i bought a obd0 dx to obd0 b16a harness and was running my car on a pr3 ecu. I decided to convert to obd1 because, 1-more tuning support, 2- because my engine is obd1 lol. So It still has the dx dash harness in it. Im just trying to work with what I got and learn at the same time. Everything is here, I just need to wire it up correctly. I checked the dizzy wiring and seems to be correct (cased the wires with a multimeter) I havent checked the small 2 wire dizzy plug yet thought. Im throwing ecl codes 6 (coolant temp), 10 (Intake air temp), and 22 Vtec pressure solenoid. My question is should my engine start even with this codes going off? Or does the ecu recognize this and not allow the engine to start? What are the things that need to be switched (wiring wise) to go from a obd0 b16a with dx dash harness to obd1 b16a? With time I can figure this out, I know Ive probably made it harder than what it has to be, but hey Im learning. I just got sick of reading pinouts and chasing wires for the past couple of days. Any help will be appricated.

Thanks Michael
 
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#2 ·
mekal said:
Alright I know this is covered all over the internet, but for my particular application I couldn't find much. Car is a 88crx dx. Its kinda of turned into a little mess. Heres my setup currently obd1 b16a, p28 chipped from phearable, obd1 dizzy, obx 4 wire o2 sensor, obd0 to obd1 ecu jumper harness, obd0 to obd1 dizzy jumper harness. In the future try not bying cdm junk.

I bought the car with a stock dx d15b2 engine and swapped in what i thought to be a obd0 b16a. So i bought a obd0 dx to obd0 b16a harness and was running my car on a pr3 ecu. I decided to convert to obd1 because, 1-more tuning support, 2- because my engine is obd1 lol. How did you convert the car to mpfi? Also what hardness did you by and from who?

So It still has the dx dash harness in it. Im just trying to work with what I got and learn at the same time. Everything is here, I just need to wire it up correctly. I checked the dizzy wiring and seems to be correct (cased the wires with a multimeter) I havent checked the small 2 wire dizzy plug yet thought. Im throwing ecl codes 6 (coolant temp), 10 (Intake air temp), and 22 Vtec pressure solenoid. My question is should my engine start even with this codes going off? Or does the ecu recognize this and not allow the engine to start? Dx dash harness does not matter. Even with those codes you car should still start. Check the basic even if you done so far. Are there 3 grounds on the motor, if so what are they? Do you have spark? Open the dizzy do you see any red dust?

What are the things that need to be switched (wiring wise) to go from a obd0 b16a with dx dash harness to obd1 b16a? With time I can figure this out, I know Ive probably made it harder than what it has to be, but hey Im learning. I just got sick of reading pinouts and chasing wires for the past couple of days. Any help will be appricated. First thing to do is go from dpfi to mpfi. Second would be to added in the jumper harness that takes 2 seconds to do. Last would be to added vtec wiring and knock sensor.

Thanks Michael
Ok first please try spacing things out, if you put a whole bunch of text your chances of being help diminish.
 
#3 ·
The dpfi to mpfi was included in the harness that I bought from monotech. The wires were labeled to go to the corresponding ecu pins. An engine needs three things to run. Fuel, ignition, and oxygen (and compression).

I positively have ignition. I checked for spark at the end of each ignition lead.
I positively have oxygen.
I positively have compression. The engine has 50,000 and it ran beautifully before the conversion.
Fuel is questionable. I have obd0 injectors with a resistor box. Heres what i have
A1=injector1
A3=injector2
A5=injector3
A7=injector4

Where do the other wires go that come off the injectors? I thought the engine should run even with these codes. I havent checked my second dizzy plug wiring yet, the two wire one. Thats tach and 12v correct? If the fuel setup is good than maybe the ignition is off due sensor wiring. What are the 3 grounds on the engine that your talking about? thanks for your help michael
 
#4 ·
mekal said:
The dpfi to mpfi was included in the harness that I bought from monotech. The wires were labeled to go to the corresponding ecu pins. An engine needs three things to run. Fuel, ignition, and oxygen (and compression).

I positively have ignition. I checked for spark at the end of each ignition lead.
I positively have oxygen.
I positively have compression. The engine has 50,000 and it ran beautifully before the conversion.
Fuel is questionable. I have obd0 injectors with a resistor box. Heres what i have
A1=injector1
A3=injector2
A5=injector3
A7=injector4

Where do the other wires go that come off the injectors? I thought the engine should run even with these codes. I havent checked my second dizzy plug wiring yet, the two wire one. Thats tach and 12v correct? If the fuel setup is good than maybe the ignition is off due sensor wiring. What are the 3 grounds on the engine that your talking about? thanks for your help michael
I like checking for spark the old school way, pull a wire and put a spare plug on it. There should be 3 grounds, on on the valve cover, one on the trans, and one on the t-start. The t-start one is the main ecu ground. Even if they are there clean them up. Is the dizzy a known good working one? Is the ecu a known good ecu? Even with the codes it should run!
 
#5 ·
well im going to work on it right now for a couple of hours to try and figure things out. Ive got a ground on the valve cover and transmission. They are clean and sanded down to bare metal. The t-start is located where? Does it come off the starter into the fuse box? The distributor is producing spark, ill take a quick peak inside it today. The ecu is from phearable.net i hope its working lol. Havent used it in another application yet. Thanks for the quick responses though. All post update ya when tonight after working on the car.

Thanks Michael
 
#6 ·
mekal said:
well im going to work on it right now for a couple of hours to try and figure things out. Ive got a ground on the valve cover and transmission. They are clean and sanded down to bare metal. The t-start is located where? Does it come off the starter into the fuse box? The distributor is producing spark, ill take a quick peak inside it today. The ecu is from phearable.net i hope its working lol. Havent used it in another application yet. Thanks for the quick responses though. All post update ya when tonight after working on the car.

Thanks Michael
t-start= thermostat make sure that ground is on.
 
#7 ·
there was no ground on the thermostat housing.. I took the engine harness out to extend the wires to make it look nicer and I have 4 wires going into two ring terminals that were bolted down somewhere in the starter area(which is close to the thermostat so I tryed grounding those to the thermostat still nothing. I cant even get my cel to throw codes at me consistantly. Im grounding out the SCS wire to read codes but it will only throw codes out every once in a while.

I checked spark again and this time with the plugs on, and still had spark. What do you think about my fuel injection setup? Should i have to modify the wiring on that in anyway going from a obd0 b16a to obd1 b16a? Ive got the obd0 injectors w/ resistor box.

thanks michael
 
#8 ·
mekal said:
there was no ground on the thermostat housing.. I took the engine harness out to extend the wires to make it look nicer and I have 4 wires going into two ring terminals that were bolted down somewhere in the starter area(which is close to the thermostat so I tryed grounding those to the thermostat still nothing. I cant even get my cel to throw codes at me consistantly. Im grounding out the SCS wire to read codes but it will only throw codes out every once in a while.

I checked spark again and this time with the plugs on, and still had spark. What do you think about my fuel injection setup? Should i have to modify the wiring on that in anyway going from a obd0 b16a to obd1 b16a? Ive got the obd0 injectors w/ resistor box.

thanks michael
You shouldnt have to change anything as far as wiring goes. Something doesnt seem right, could be a bad chip. Try any obd1 civic ecu doesnt matter what kind of civic.
 
#9 ·
I looked at all my grounds coming out of the obd1 ecu and something doesnt match up. It was at the end of the night though after I had been messing around with the car for a while, So I gave up for the night. Ill get back to it sometime later this week.

Question: What ecu pin number does the RPM lead from the distributor go to?

Ill try and get a hold of a civic obd1 ecu.

Thanks michael
 
#11 ·
Alright anyone want to rent me a ecu and dizzy lol? Is there anyway of testing these two? Take a look at my dizzy wiring and let me know if this is correct

OBD1 dizzy wire color-------------------------------ECU pin
Yellow green (ICM)-----------------------------------A21
Blue Green (CKP+)------------------------------------b15
Blue yellow (CKP-)------------------------------------b16
Orange (CYP+)----------------------------------------b12
white (CYP-)------------------------------------------b11
Blue orange (TDC+)----------------------------------b13
white blue (TDC-)------------------------------------b14

Ive been reading to just match up color for color besides the thick white wire, but my application was different, the person who made the engine harness didnt use the original wiring. There for I cant do this color for color thing. Ive tested with continuity all these connections and this is exactly how it is on my car. I didnt put down the tach and 12+ because i believe those are correct.

As for the color of the obd1 dizzy wires coming off the dizzy. I got this information from a online source so i dont know if its 100% correct. Also I will add that I have been blown 2 15a ecu fuses on this setup? Grounds are good and havent messed with them. The following wires are grounded coming from the OBD1 ECU

A23
A25
A26
A24
B02
B01

So ya im starting to lean towards the possibility that either my ecu or dizzy is messed up, but feed back about the dizzy and ground wiring would help me confirm this. thanks for your help by the way crxvtec91.

Michael
 
#12 ·
Your going about it a bit wrong. First NEVER setup anything color for color! It should ALWAYS be sensor to sensor!!!

Second IF the car was running good with all the obd0 stuff then wiring "SHOULD" be good. There for swaping over to obd1 would be as simple as slapping in the 2 jumper harness, ecu, and dizzy; then fire. So either A, try the obd0 stuff just to make sure the car still runs. Then if it does try another obd1 ecu and dizzy. Any civic obd1 5spd ecu will run the car for testing, and a z6 dizzy can be hack up to run the motor.
 
#14 ·
Havent been working on the crx lately, but got back into it tonight. Heres whats happening now.

Voltage is coming on 12v at each injector when key is turned on.
the dizzy is sparking when the engine is cranking.
i hooked up my obd0 pr3 ecu and the engine did not start in limp mode, and there were no cels.
Cel is sold when p28 is hooked up and the scs is grounded.

i will do a ignitor and coil test on my distributor soon, but does anyone have an idea of whats going on from the above symptoms?

Thanks Michael
 
#16 ·
car ran fine on pr3 and obd0 equipment. How likely is it that a ecu chipped from Phearable.net is bad? I mean they are a pretty reputable company. I dont know still looking for someone with a cheap obd1 civic ecu or one to barrow. No one around me has hondas lol. They put in a zif socket so cant i just order another chip and put it in if i confirm thats the probelm. More troubleshooting is needed in the mean time.

thanks for your help though
 
#17 ·
mekal said:
car ran fine on pr3 and obd0 equipment. How likely is it that a ecu chipped from Phearable.net is bad? I mean they are a pretty reputable company. I dont know still looking for someone with a cheap obd1 civic ecu or one to barrow. No one around me has hondas lol. They put in a zif socket so cant i just order another chip and put it in if i confirm thats the probelm. More troubleshooting is needed in the mean time.

thanks for your help though
Anything is possible. You can send the ecu to Xenocron and have them test it to confirm it is good. Or get another one to try.
 
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