Hi guys long time H-T user, first time writing a thread. I have a 2000 2 door civic coupe with a b20 v. I recently swapped in a a new one though as the old b20 v's thrust and crank bearings went while driving. But the old b20 was a jdm b20b with a b16 head. The new one is a usdm b20b4 with a b18c head. Now I'm using all the OBD1 components that ran the old setup but I'm getting a trouble code 0. Solid CEL, crank all day til my battery dies, no start. I was wondering if there were any differences in the setups that Iay have overlooked as far as ecu compatibility or sensors that I may have messed up or what not. Any information will be appreciated. That ks in advance

 

Maybe check for spark? If none, is your ground to thermostat connected for the ecu? If your getting spark, are you getting fuel? Maybe a bad main relay?

 

from my understanding, code 0 normally means your ecu is not reading.

check your thermostat ground. if that is ok, find another obd1 ecu, swap it in to see if the car fires up

 

What does a "Code 0" look like ? How do you read it ?

 

Hi thanks for replying guys. Ok I have spark, Im not getting fuel, I triple checked the thermostat ground and all the other earth grounds under the hood. (Radiator support to the valve cover, body to the trans, and the battery to the shock mount ... All good) I was getting fuel prime when it first started doing this but now, today after turning the key I'm not getting fuel prime so I ordered a mitsuba main relay from eBay. But I won't get it for a couple of Hi thanks for replying guys. Ok I have spark, Im not getting fuel, I triple checked the thermostat ground and all the other earth grounds under the hood. (Radiator support to the valve cover, body to the trans, and the battery to the shock mount ... All good) I was getting fuel prime when it first started doing this but now, today after turning the key I'm not getting fuel prime so I ordered a mitsuba main relay from eBay. But I won't get it for a couple of days. I bench tested the main relay I have now, and to my understanding, I use a 9v batter and test clips and there are 3 tests where I power 2 tabs and check 2 other tabs for continuity. It passes all but the last test. So I don't know.if there are any other tests in can do till the new relay gets here. And I don't ok now anyone with an extra one to that I could use to test. And to answer the last reply, I got code zero by dioding the diagnostic wires under my glove box and the CEL didn't change at all. It's solid with the diode in the wire and when it's out.

 

If your CEL is "On" when the ignition power is on, and you then short the service connector to attempt to check the code, and the CEL stays illuminated without blinking, this could be a bad ECU. However, this can also indicate that the engine harness ground isn't appropriate... and remember that just because the ground is tight doesn't mean that the ground is good. Painted blocks (grounds don't work well through paint), loose bolts holding the thermostat housing to the block, or a paper gasket between the thermostat housing and the thermostat cover (if your engine ground is bolted to the thermostat cover) can cause a failure of proper ECU function. Remember, capacitors fail in OBD-1 ECU's every day... these computers are operating way past their original designed lifespan. You cannot rule out an ECU failure... it is best to test your ECU in another vehicle (or test a known good ECU in your car) to verify ECU operation.

Lastly, if you have a "chipped" ECU, there is a possibility that you have what is typically referred to as a "phantom code". These are codes that are incongruent to the calibration and ECU platform used: Two examples of this would be 1) The Knock sensor not disabled in a calibration installed into an ECU without a Knock board/circuitry. 2) VTP enabled in a calibration installed into a JDM ECU. These issues may illuminate the MIL yet when you check the SCS for codes, no blinks occur and the light remains solidly lit.

 

Thanks JRcivic1, ok so I bought a p28 ecu the other day. It was chipped already and I had it base-mapped for b20 VTEC, and I put it in my car and it m still getting a solid CEL. And I don't know anyone with a Honda running OBD1 so I cant check my ecu in another vehicle so I'm stuck on what to do next... (SMH) . If its getting a "phantom code" how would Ingo about finding out why or how do I fix it? Thank you for anybody who has helped already and thanks in advance to anyone that can help me with this. It's my only car at the moment and riding my 24 inch haro everywhere isn't the worst thing ever, but it's definitely not fun in the cold lol.

 

Do you by chance have any plugged mixed up and plugged into the wrong sensor causing your cel? Like possibly the tps and map switched?

 

When you turn the key to the ON position, do you hear the fuel pump prime and the main relay click ?

 

Well, I'm willing to bet like mentioned above you might have some plugs mixed, assuming by saying B18C You are referring to a GSR head, if so The GSR intake manifold has a few more sensors compared to the B16 head/ manifold you had. Double check you have everything plugged correctly. MAP, TPS, IACV,