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Discussion Starter · #1 ·
Well guys, as you know im a newbie to hondas. I just got my CRX last night and its got a check engine light on, its a 91, with a D15B. The person i bought it off of said the engine light is on because its a JDM ECU? Only reason im wondering what those codes are, are because i was driving today and it stumbled REAL hard, kinda felt like a turbo car hitting fuel cut, so im wondering if the code will give me some insight.

Now im not sure if its a JDM D15, and since its a JDM ECU, i dont know, i snapped some pics to try and make it easier...

ECU



Isnt my hand sexy?!?!
Engine
 

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Look under the passenger side dash for the blue 2 pin connector used in OBD1 to check the codes. We have them too. Use a screw driver or wire to connect the bridge and count the blinks.

You don't get codes cause it's a JDM ECU, you get codes cause something is wrong. Tell us the codes when you pull them.
 

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Discussion Starter · #3 ·
yeah, "its a jdm ecu" didnt make much sense to me, i mean, im new to hondas, but ive been a mech/working on cars my whole life. I didnt think that was right, but thats why i posted up here, to see
 

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Discussion Starter · #4 ·
Ok, that was kinda odd, never had a code flash like this before, hopefully it will make since to you guys . I got a QUICK flash, like 1/2 sec, then 2 1-2 sec flashes, then another 1/2 sec flash. so it was quick, slow, slow, quick. Which if i understood right, is 121, but that doesnt even seem to be a code, so i dont know
 

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Discussion Starter · #13 ·
ok O2 sensor, any universal 1 wire will work right?
its pretty beat up


and what is this sensor with nothing plugged into it? and should there be something plugged into it?


And where do i locate this vtec solenoid?
 

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You have a TB mounted MAP sensor, get rid of the firewall mounted one. You will have 1 extra little plug left over. Cut the loom to stretch the wires, trust me they will stretch. The map sensor mounted on the firewall can be unbolted. Since you might not know what it is since you didn't know that the shown sensor is map sensor, the map sensor is the one with an electrical plug going into it (well 2, ones an extra with obd1), it also has vacuum lines going thru it and it's bolted to the firewall, that should be enough for you to figure it out. Block off the vacuum lines that aren't needed anymore. TB mounted map sensors are nice IMO.

Yes, that's a vtec solenoid. The grey plug pictured is where A4 on your obd1 ecu should send a 12V at whatever rpm it's set at to engage vtec. Code 21 = no vtec.

Replace your O2 with a known working one. When I did my OBD1 conversion I made a 4 wire O2 sensor. You would wanna get one for whatever car you have right now (88-91 crx or civic).
 

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Discussion Starter · #16 ·
MAP sensor is on the list, but its working ok right now, so im not ganna screw with it. Sun morn im ganna go get a O2 sensor and replace it, i jumped the Vtec solenoid, and the Vtec oil pressure unit, which is supposed to make Vtec work, and keep the light from popping up, figure its a temp. fix untill i get time to actually track down whats really goin on.
 
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