iite so i bought a jdm d15b motor (obd1) and i put it into my 1991 si hatch.. i am still using the obd0 si wire .. i am using my obd0 manifold on the new motor also.. i put new intake manifold gasket n tq it down to the right specs.. i also re wired my dizzy.. i am using a obd1 dizzy and i connected the obd0 connector to it so it can work.. the obd0 dizzy would not line up to the holes in the obd1 motor..now problem is that the car will not pass 3500 rpms.. i have the step up harness from obd0 to obd1 and i am running a stock p28.. also i used a diff ecu n still wont revv pass 3500.. i tried a diff map sensor n still nothin .. the step up harness i got from rywire. com.. i told my dizzy was good and i tested it n im gettin more than enough spark from the dizzy.. im just at a lost as to what the problem could be as to why its not able to revv pass 3500 rpms.. please lemme know anyhelp would help

 

bump

 

You're in limp mode. You need to check your ECU for codes using the CEL flashing to tell you what is wrong. Post up the code for more help.

 

bumpppp

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ...:::MaRk:::... &raquo;</TD></TR><TR><TD CLASS="quote">bumpppp</TD></TR></TABLE>

Idiot, he told you to pull the codes and post them, there's no need for a bump.

Pull the damn codes off your ECU so somebody can help you.

 

Check your code (as stated above), then post what codes are present. If you are in limp mode, it is because the ECU is reading a problem. The Rywire harness has 2 wires (blue and orange I think) that you use to read the codes (connect them together and count the flashes on your CEL for codes). Also are you using a 4-wire O2 sensor, a P28 ECU will be looking for that. Please don't bump again until you give us something to help you with.


Wizco beat me to the reply ( I had to leave the computer before I finished my post).


Modified by rustbucketrex at 2:00 PM 6/24/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rustbucketrex &raquo;</TD></TR><TR><TD CLASS="quote">Check your code (as stated above), then post what codes are present. If you are in limp mode, it is because the ECU is reading a problem. The Rywire harness has 2 wires (blue and orange I think) that you use to read the codes (connect them together and count the flashes on your CEL for codes). Also are you using a 4-wire O2 sensor, a P28 ECU will be looking for that. Please don't bump again until you give us something to help you with.


Wizco beat me to the reply ( I had to leave the computer before I finished my post).


Modified by rustbucketrex at 2:00 PM 6/24/2008</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">

Idiot, he told you to pull the codes and post them, there's no need for a bump.

Pull the damn codes off your ECU so somebody can help you.</TD></TR></TABLE>

will do thanxz

 

Hurry up with those codes man. Should take you 5 minutes.. Id like to help out with your problem.

 

i have got the same prob, but mine goes in and out. sometimes i will be in limp mode and other i am not. but i have the stock ecu for the jdm d15b, and it doesnt have any lights (cause its jap?). so is the only way to find what codes im getting to take it to a shop? mine is also completely switched to obd1.

 

if you bought a conv harness you should be able to jump 2 wires together to get it to flash the codes - read your instructions that came with the harness mine are yellow and black as I doubt they would have screwed you with no way to chk codes.

 

got the harness off a guy who wreckd his car that had the same swap. dont know where it came from or who made or nothing. i gues i will try to find his email or something and track down where the harness came from. till then i will just deal with it. it doesnt happen all too often and i dont drive much. if anything i will just work and extra weekend and have someone else fix it. if i try anything with the wiring i will end up [freak]ing something up, wich would be ok if this car wasnt my DD.

 

Don't bother taking it to a shop. They'll have just as hard of a time figuring out the wiring and charge you an arm and leg for it.

Your harness should be wired to use the OEM timing jumper to check CEL but some don't There is a single wire you put to Ground that will make the CEL flash. I'm on my phone but you can search for OBD1 pinout for the Service Check connetor (SCS is the abbrv. listed most IIRC). Regardless of the conversion harness, just take a wire that you ground to the body, put it to that SCS pin/wire and you'll at least be able to read your code(s) and go from there.

When I get home after work I can get you the correct pin to short to ground if you don't find it first.


**EDIT**

Wire Color: BROWN
OBD-0: (B20)
OBD-1: (D04)
Service Check Connector



Modified by BlueCrxNC at 5:13 PM 6/25/2008

 

cel? scs? sorry man you might have to dum all that down for me? till this point all i have ever done is swapped mtors that were simple plug and play, i have never had to dick with any wiring or anything yet.

 

found the prob i thik, after taking a close look at the conversion harness plug, it is the harness that converts the plugs for the american ecu so it morks for the jap ecu, but two of the pins broke... dont know how to explain it reallly. but i ting i can fix it.

 

CEL is check engine light (in your dash cluster).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skidmarkroyalty &raquo;</TD></TR><TR><TD CLASS="quote">found the prob i thik, after taking a close look at the conversion harness plug, it is the harness that converts the plugs for the american ecu so it morks for the jap ecu, but two of the pins broke... dont know how to explain it reallly. but i ting i can fix it.
</TD></TR></TABLE>

Great! That's probably your issue. Did the metal pins on the connectors break or the wire/solder joint just pop free? Glad to hear you think you can fix it.

 

yeh one of them broke and the other one the wire just came off. its funny too because i always made my girl feel bad by saying she was bed luck, cause EVERY TIME she would ride with me my **** would go into limp mode. turns out her feet must have been making those wire loser and loser every time she got in the car. i couldnt see that the wire pin was broke cause the shrink wrap was holding it in place, but it finally completely broke off yesturday so i seen it today when i was working on finding the prob. i hopped on my bike and after going to 6 different shops no find a replacement pin (never found one), i took it to an audio shop by my house and the sodered (sp?) it up without a new pin. drove it around the block and it didnt go into limp mode so i think i am good. thanks for the help guys, (now i know what a cel is).

 

Excellent. I remember back when I ran a homemade OBD-1 Conversion harness on the old CRX... the wife kept stepping on the ECU and wiring... scared me so bad that instead of just putting it under the metal cover in the floorboard I made a new harness to put all the wiring under the center console then underneath her seat! Ha, can't step on it now. Currently just hardwired the OBD-1 plugs in and run the metal cover

 

alright... so that fixed the problem of my car going into imp mode as soon as it is turned on... but now it goes into limp mode after a few miles of driving... i am thinking after it comes out of closed loop it realizes somthing is wrong. the RPMs flutter a little like it going to stall out and then it goes into limp mode. but while in limp mode it acts like it is getting too much oxygen, it acctually feels like there is water in the gas or something (only in limp mode). so i am thinking o2 sensor. i am swapping it out to see if it changes. but i also tried shorting the brown wire to ground, nothing happened. . . any other ideas on how to read my codes?

 

I would guess that's an O2 problem as well.

 

well for the first few months on the motor i was running my old o2 sensor of the original motor which was only a one wire o2 sensor... and then i finally got a new 4 wire... and i cant remember if my car started pulling this limp mode **** before or after the new o2 sensor. seems wierd that it wasnt going into limp mode all that time from the 1 wire sensor, cause its a 95 jdm d15b, wich calls for a 4 wire. i dunno ill find out soon when i take it out to the bowling ally!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skidmarkroyalty &raquo;</TD></TR><TR><TD CLASS="quote">but i also tried shorting the brown wire to ground, nothing happened. . . any other ideas on how to read my codes?</TD></TR></TABLE>

If that didn't make the CEL come up with the code(s) then that is one shitty jumper. Double check that the following is hooked in properly.
OBD-0 (B06) GREEN/orange
OBD-1 (A13) GREEN/orange
Check Engine Light (MIL/WARN/CEL)

Is you CEL light bulb good? (comes on during power on/start up) What I've told you to do is directly at the source of the codes. There is no more direct way to check unless you want to wire in a light bulb to the above wire, add 12v to the other side of bulb and short out the wire I told you before. That's it.

We're pissing into the wind trying to help you without ECU error codes!


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skidmarkroyalty &raquo;</TD></TR><TR><TD CLASS="quote">well for the first few months on the motor i was running my old o2 sensor of the original motor which was only a one wire o2 sensor... and then i finally got a new 4 wire... and i cant remember if my car started pulling this limp mode **** before or after the new o2 sensor. seems wierd that it wasnt going into limp mode all that time from the 1 wire sensor, cause its a 95 jdm d15b, wich calls for a 4 wire. i dunno ill find out soon when i take it out to the bowling ally!</TD></TR></TABLE>

The motor doesn't require a 4-wire O2 Sensor. The JDM D15B VTEC came out of the JDM Civic VTi using a P08 ECU. The ECU determines what you need... P08 = Single wire O2; P28 (USDM D16Z6) = 4-Wire. *There are ways to make either ECU control/remove it's OEM function, but that requires electrical work internal to the ECU.


Modified by BlueCrxNC at 3:47 PM 7/4/2008

 

i know the cel is good, it is on 24-7. so what happens if i have the P08 running on a 4 wire sensor then? also someone told me i shouldnt run a 1 wire o2 sensor with a header for some reason. some thing about the sensor not getting hot enough or something... it was a while ago... know anything about it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skidmarkroyalty &raquo;</TD></TR><TR><TD CLASS="quote">i know the cel is good, it is on 24-7. so what happens if i have the P08 running on a 4 wire sensor then? also someone told me i shouldnt run a 1 wire o2 sensor with a header for some reason. some thing about the sensor not getting hot enough or something... it was a while ago... know anything about it?</TD></TR></TABLE>

People are correct about it being better to run a 4-wire if your O2 is further down the exhaust. All the 4-wire has is a small heating element to preheat the sensor so you are getting more accurate readings while the exhaust gases are colder than when the motor is fully warmed up. If you were running a P28 ECU then the 4-wire would be required of you unless you remove the code for the heater in the programming. You are okay to wire in the 4-wire to the P08 as well BUT it will NOT use it/control it unless you've modified the ECU. I did this to my last P08 that I am running.

I made a .DOC file of all the collected works I could find about modifying the P08 ECU. Here is what I have for the 4-wire O2 Conversion:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">ONE-WIRE OXYGEN SENSOR TO FOUR-WIRE CONVERSION:

For JDM ECUs that lack the O2 heater circuitry, such as the P08, simply add a SMT version of the 2N4401 (general purpose NPN switching transistor) to location Q15 on the underside of the PCB. The proper part number for the transistor is MMBT4401, and they are readily available through retail suppliers such as http://www.digikey.com/

I've had success using transistors from P2K (carb) ECUs (also on AT control
units perhaps?). They are marked "86" horizontally and "45" vertically.
I've used 2N4401 for the USDM OBD1 C144 transistors and it worked fine. May want to try the SMD version.

To be sure O2 heater is working you should see about 200mA thru A6.
For JDM style ECUs heater is controlled by Q15 (reverse side of board opposite end to plugs) and should be labeled L30 (i.e. the equivalent for Q30 on 11F0/1720). This is helpful in converting P29/P8 JDM to P30.
</TD></TR></TABLE>

I wouldn't modify the ECU if you are not familiar with soldering Surface-Mounted components (ie. very small, delicate). You can leave the 4-wire O2 hooked in just realize it's not being controlled by the ECU. You could manually turn the heater of the O2 on but you have no way to regulate the temperature.


Modified by BlueCrxNC at 9:21 AM 7/5/2008