I just picked up a 88 hatch with a b18a1 swap. On the block stamp, the code below b18a1 starts with a 3, leading me to believe the engine is from a 92-93 integra ls. However, it has a pr4 ecu, which my research indicates comes from the 90-91 ls, which makes less power than the 92-93 ls. Do i need a different computer to fully realize my engines power? Any information would be appreciated.

 

Poking around under the hood a few minutes ago and found pr4 stamped on the head. this only confuses me further. anyone have any info?

 

pr4 is the correct ecu for your motor

 

Ok, thanks. Is it definitely the 92-93 engine?

 

90-93 is b18a1 94-01 is b18b1

 

a pr4 for a 92-93 is a obd1 ecu which im sure u wont have unless u have a obd0-obd1 jumper harness. im sure u have the right ecu if it plugs up to ur 88civic. the only problem u may run into is that u MAY HAVE an automatic ecu instead of a 5speed ecu

 

i believe the pr4 came in both obd0 and obd1 versions so it depends on which one he has. if there is a jumper harness then obviously he has the obd1 version. also how can you say he has an automatic ecu?? he hasn't given the rest of the ecu code. according to hondata:

The last 3 characters are broken down into 3 parts. "A" generally is used for US ECUs. "G" is European, and "J" is Japanese. The second digit "0" typically means manual transmission, where a "5" means automatic transmission, and the last digit "1" is the version number.

 

It doesn't look like i have a jumper harness. the code reads a02, so its not an auto ecu, but how can i tell for sure which b18a1 and ecu i have?
PS- whoever put this car together was completely retarded, i'm kinda surprised it actually runs.

 

it dosent matter which b18a1 or pr4 ecu you have if you dont have a jumper than your setup is obd0 , just to let you know the only difference between the 90-91 abd 92-93 b18a1 is the cams nothing else , so stop thinking you have something wrong or dif

 

Right, but if my engine is from 92-93 then obd0 is not the correct ecu.
the 92-93 b18a1 makes about 10 more hp and 5 ft/lbs, and like you said it has different cams, and therefore requires a different ecu.

 

check the date stamped on the head.

 

Ok its a 92. thanks kyden and everyone else. So now i need a odb1 ecu and jumper harness right?

 

leave the car the way it is, i doubt youll get more power with going to a obd1 pr4 ecu... and no you cant just get a jumper harness...

to go obd1 you need the following or it wont run...

obd1 ecu
obd0-obd1 jumper harness
obd1 non vtec b series distributor...

are you ready to spend 400 bucks just to go obd1? not worth the money.. then if you dont chip the ecu you need a 4 wire o2 sensor which is another 80 bucks from autozone

if the car runs and it aint broke just leave it alone

 

I don't think you get it. my engine is from a 92 integra. it has different cam profiles and was originally an obd1 engine. I don't think its running quite right with the ecu from the old engine.
OR are you trying to tell me that the different cams will run the same with either ecu?

 

bingo you finally got it "the different cams will run the same with either ecu"

 

yea honda didnt make the cam profile that much different between the 2 engines, i mean how much does the b18a1 make and how much does the b18b1 make for power, like 4 hp difference? its not gonna matter...

if you go to obd1 to tune your car and extract more power then yea its worth it, but if you go obd1 just for the hell of it then your wasting your money

 

Well i was planning on doing some tuning and going turbo in the future as well, so i will need to go obd1 at some point, but i will remove it from my priority list. Thanks for the help guys.