1991 B18a to 1994 B18b

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Sam P Son

New Member
Years ago I swapped a B-18a1 (1991) into a Honda Civic DX (4dr) with a pr4 computer at obd0. Well, it's been fun with B-18a1 but now my motor is spitting smoke at 2500rpm without hesitation.
My question: Can a 1994 B-18b replace the 1991 B-18a with the same pr4 computer? The catch is that I have a CA Ref Tag. I would still want to be legal with the exchange from 1991 B-18a to 1994 B-18b. Is this possible? Does anybody have any information or know where information is for the type of motor exchange I have explained above. Thanks ahead of time for any help.
 
1991 B18A to a 1994 B18B

OK, maybe a re-phrase is in order, no replies yet.....
Question: Can I use my PR4 ecu you that I was running with my 1991 B18A to run my newmotor, a 1994 B-18B?:confused:
Thanks ahead of time.;)
 
IIRC, the PR4 is the ECU that runs the OBD0 LS motor. According to our ECU list in the reference section, the P74 or P75 is what runs the 94 OBD1 LS.

https://hondaswap.com/reference-materials/honda-ecu-list-29129/

I suppose you could convert the motor from the 94 LS to OBD0, but I have never done it, nor have heard of any advantages of doing that. However, it could prove beneficial for you if you are looking to keep your car within "ref" specs.

As for the ref'ing for Cali, I don't know anything about that. There are lots of guys from your neck of the woods that might be able to answer that better than I.
 
Your upgrading to a new engine so i think you'll be fine, and i can't see them saying you would have to run it obd1 since the car is obd0 to start with. So long as your not downgrading i dont think you will have any issues. the obd0 pr4 will run the b18b just fine. just swap your dizzy and injectors over to the new engine. depending on what year b18a you have you may have already moved your coolant temp fan switch from the back of the block to the side of the head on the thermo housing. if you haven't had to move it yet, you will once the b18b is in there.
 
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