So I currently own an Ej1 with a b16a2 swap and i'm using an obd2 gsr wire harness. my question is.. will i need a jumper harness if i have an obd1 p28 ecu in my 93 civic with a b16a2 engine???

 

You would be right. You need a jumper harness that goes from OBD2 EWH to OBD1 computer.

 

obd2b->obd1

 

is it also true that i can use an obd1 b16a ecu on a b16a2 and still get away with it w/o the jumper harness?

 

Hold on now, you're using the GS-R engine harness correct? Plugged into the the stock Civic Cabin harness at the shock tower plugs right? In that case no you don't need (nor could you use) an adapter harness. Simply use an OBD1 ECU.

 

to my understanding the obd1 p28 ecu would have to chipped in order to function with the b16a2 engine right???

 

Correct. It'll run, but it wont run properly until its chipped.

 

are you positive it'll run? can i drive it around with a virgin p28 until i can get it chipped???

 

yes you can run a b16 on a stock p28. it will run a tad lean, but will function properly (ie vtec engagement)

 

but in for it to even run i must first get the jumper right??

sry for all the questions im still learning =]

 

your car is obd1 to begin with so no you don't need a jumper harness

 

you would be wrong, why is it so many people on this site answer questions they don't know the answers to?

 

the b16a2 is a obd2b enigine, so i would assume that you need to get a 92-95 vtec, engine wiring harness for it to work in your chassis and the p28 will plug right in

 

that would also work, but the all the teg harnesses are 2 piece just like the 92-95 civic harnesses. so it does not matter if the teg harness is out of a later year. The ek civic harnesses are one piece and thats why they wont work in eg's and tegs.

 

/\ /\, didn't know that all teg harness are 2 piece, good to know for future swaps