martiniracing

my car is a 98 ek hatch with a jdm b18c swap. it's currently running on chipped p28 (with jumper) harness and i'm having alot of weird issues with the ecu. it would run super rich if it's cold with CEL on, but when the engine is beginning to get warm, i can reset the CEL by turning the engine on and off.

anyways, what ecu should i look for? would it be a jdm or usdm p72 and would it be pretty much plug and play to my 98 harness (with jumper harness removed)?

Bennyboy1717

JDM p73 ITR obd2a will plug straight into your ek hatch . . . thats what im using in my 96 hatch at the moment and it runs great!!!

thumper64

Is it a Type R swap or regular B18C? A OBD2A P72 would control it I believe. I still have one I'm trying to get rid of...

martiniracing

it's a regular b18c (sir/gsr) i think, cause it's got a black valve cover, but with lsd tranny

i just bought a p72 from ebay, so i won't need to switch around or do any wiring?

i haven't really looked, but does the jdm motor NOT have cold start injector?

sam

thumper64

Depending if it's JDM or not, you should be ok. The JDM motors don't have a knock sensor, but a USDM ECU will look for one. It can be bypassed or added, but it's not a huge deal.

What's a cold start injector? I've never heard of that.

jkalex05

pm monotech from the forums, he does some bad *** ecu's and can make a mapping just for your car. hit him up.

or I got a type R p73 ecu if your interseted

thumper64

He just got a P72 and it's the right ECU for a regular GSR B18C. Now the issue is only whether or not it's JDM or USDM.

martiniracing

the motor is definately jdm.

cold start injector usually is found on the intake manifold and helps prime the intake chamber with extra fuel on cold start up's

if i just plug in the usdm p72 and assuming i don't have any other problems, would it throw any codes since it's not being used in a dc2?

sam

thumper64

The USDM ECU will throw codes I know, I want to say for the knock, crank fluctuation sensors and maybe another. Knock can be added by drilling/tapping a bracket (like the alternator) and screwing it in. The crank fluctuation can be added by putting a new oil pump on (good idea anyway) and you'll need the sensor and I think a piece or two behind the crank pulley. If you find the sensor used, it should be cheap.

jkalex05

I got the ECU you need pm me =p

martiniracing

so i assume the jdm motors doesn't have both?

i found a crank fluctuation bypass trick. is that a good idea?

what are the diff. features comparing a jdm p72 and usdm p72?

thumper64

There are tricks for most anything, or adding sensors is cheaper than buying another ECU.

I am not totally sure about differences. I know the two aren't identical, but you should be fine if you take the time to see what you need. I am pretty sure someone has run a JDM motor and a USDM OBD2 ECU and documented it.

martiniracing

Judging from my friend’s experience with jdm ecu’s, he said they usually don’t offer as much fuel economy has the usdm ecus. And I also hear they have immobilizer (or maybe it’s the other way around)?

Bennyboy1717

JDM p73 will not look for several things that a USDM will . . . including secondary o2 sensor and crankshaft position sensor and knock sensor. They do not offer quite as good of fuel economy as a USDM one will but for most of us thats kinda irrelevant lol

Shdw b18c

The only difference on jdm engines is that they do not have vtec oilpressure sensor and no secondary o2 they have everything else i just did my swap. if u bought jdm ecu ur ok if u didnt then just bypass the vtec oil pressure switch and add secondary o2. Its that simple u have to make absolutly no other mod u dont have to add nothing. Jdm motors do have knock a sensor.…

martiniracing

okay, i'll try the things suggested and keep you guys posted! thanks

sam

alacard

I didn't read every post carefully, but I don't think anyone mentioned USDM p72 ecu's coming with immobilizers. You will not be able to start your car without getting that immobilizer removed. JDM b18c's might be immune from this...but I have no idea.

thumper64

I have a USDM P72 in my hatch right now, and nothing has been tampered with in it and it works fine. There is no immobilizer. That's on newer cars.

alacard

Sorry, sorry. I should have been more specific. The obd2b's have the immobilizer.

martiniracing

gotten a usdm p72 obd2a, cause the motor turned over after installing the one i got from ebay. so there's no immobilizer

when i plugged it to a scanner, it was looking for the secondary o2 sensor (p0141), eld (p1298, and i dunno why, maybe cause i had the car parked for a while and the alternator is working really hard?) and CKF (p1337)

wasn't looking for knock sensor though, maybe that was already rigged

ON A SIDE NOTE:

if i have a test pipe but running the secondary o2 sensor aft cat, would it still throw a code?

thumper64

I believe the CKF sensor is at the front of the motor, on the oil pump. You need the sensor and a different part that goes on the crankshaft

ELD I don't have any knowledge about.

The motor will throw an O2 sensor code still because the second O2 sensor should read different than the first. With a test pipe like that, the ECU thinks you just have a bad catalytic converter. Either bypass it or do the spark plug non-fouler trick, cheapest and easiest option there is considering you can go back to emissions legal if you have to very easily.

martiniracing

i'm just gonna by-pass the ckf

okay i found the spark plug non fouler trick

http://www.energeticforum.com/renewa...n-foulers.html

so i should do the non-fouler trick to sensor 1 i guess.