I've got a 99 LS swap that's OB2B with an OBD1 chipped P06 w/ conversion harness. I've got the standard OBD2->OBD1 LS cold idle flux problem. My questions are as follows:

1. Will my OBD2 engine harness plug + play with all the sensors on an OBD1 LS intake manifold?

2. Will my OBD2 throttle body mate up with the OBD1 manifold?

 

Help.

 

Please?

 

TTT

 

what year is it going in? this matters.

 

it's going in a 97 civic CX. The wireharness for the motor is mostly from the civic, but the entire manifold portion is from the original 99 LS harness.

 

ttt.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eran &raquo;</TD></TR><TR><TD CLASS="quote">I've got a 99 LS swap that's OB2B with an OBD1 chipped P06 w/ conversion harness. I've got the standard OBD2-&gt;OBD1 LS cold idle flux problem. </TD></TR></TABLE>

'99 integras were obd2A, not B.

What exactly is the "Standard obd2-obd1 LS cold idle flux"?
I used to have a '98 LS motor(using all obd2 components and sensors) running off an obd1 ecu and never had a single cold idle problem.

And what is using a obd1 intake manifold going to change?

As for your questions:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eran &raquo;</TD></TR><TR><TD CLASS="quote">
1. Will my OBD2 engine harness plug + play with all the sensors on an OBD1 LS intake manifold?
</TD></TR></TABLE>

Yes it will plug in, assuming you are reusing the obd2 injectors. Otherwise you need to switch the injector plugs to obd1 plugs.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eran &raquo;</TD></TR><TR><TD CLASS="quote">
2. Will my OBD2 throttle body mate up with the OBD1 manifold?</TD></TR></TABLE>

Yes.

 

It's a rather common problem on OBD2 teggy engines running on OBD1 ecu's (mostly P28's).

https://honda-tech.com/zerothread?id=1352408

https://honda-tech.com/zerothread?id=1054857

https://honda-tech.com/zerothread?id=466549

https://honda-tech.com/zerothread?id=1430321

you get the picture.

 

And no, my motor is NOT OBD2A .... it's a 99.

 

Yes it is.

Civics went to obd2B in '99
Integras went to obd2B in '00

Your motor is obd2A.

What ecu are you using?
Like I said, I ran an obd2A LS motor off a obd1 LS ecu for 2 1/2 years and never had a single problem.

And what is using an obd1 intake manifold supposed to change?
The IACV is the same, IAT sensor is the same, injector size is the same, throttle body size is the same, etc, etc.

 

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

And what is using an obd1 intake manifold supposed to change?
The IACV is the same, IAT sensor is the same, injector size is the same, throttle body size is the same, etc, etc.</TD></TR></TABLE>

Actually, The IAT is the only thing different.

 

My IAT sensor on my obd2 c5 motor is the same as the sensor on my wifes stock '93 DX motor.

If it was different, all you would have to do is swap the IAT, not the whole manifold.

 

the problem actually stems from the EVAP purge sensor. That's what's different.