sebTeggy

Hey guys,

I recently swapped in an OBD2 GS-R motor+tranny+bay-harness into my LS (OBD1) and I am making this thread to be an all-around, accurate, all-questions answered thread.

I ran into MANY problems, and am making this to add my solutions.

First, for entertainment, Ill ad some pics I tackled this swap with myself, two friends, and my pop-in-law who pulled the little honda motor around with one hand..... Hes a chevy guy . Oh and before I forget, my GF was there. She is also into integras and she helped separate the balljoints She is the ball-joint separator pro.... I should probably be scared! Just want to thank the 4 of you! This was my first swap, and I learned a lot. It was the main entry into the car world for me, as everything before this was simple bolt ons and maintenance! Thanks for helping me complete the initiation !

Here is my car:



CANADA Eh!?

The old




The goods



During



Done Job!




Just a disclaimer. This thread will mainly apply to people swapping OBD2 GS-R motors+harnesses into their OBD1 LS Integra. The opposite is much more complicated, but read my IAB section if that is your main concern. Also, it is a completely stock motor, including the dual stage GS-R manifold (which was my main problem) and getting the IABs to work. For those of you wondering if you should keep it, or get a single stage skunk2 manifold, be aware that Honda spent extensive research and ingenuity in designing two stage manifolds, and they are simply, more advanced than single stage manifolds due to their versatility. It helps GS-Rs and H22 Preludes get that beautiful torque curve. YES, H22s came with dual stage manifolds.



So, here is a bunch of problems I ran into!!!!


COMMON MYTH # 1

HTers: Oh yeah, when you swap in a VTEC motor, you just need to run 4 wires, IAB, Knock, VTEC Pressure, and VTEC Solenoid.

Answer: WRONG! This is not true! This is a very common mis-conception. People will read threads, see multiple people say it, then answer other peoples questions by saying the same thing. 90% of people spewing this information have never done a c1/c5 swap into their Integras. This might be true for some models (I doubt for civics since some of them are pre-wired for VTEC), but this does NOT, does NOTTTTT apply for Integras.

Real Deal:

You need to only run 3 wires. Here is a common pinout diagram that floats around the internet. The ones I had to run to the ECU were: Vtec P, Vtec S, and Knock. IAB doesn't need to be modified. You just move pin a20 to pin a17 and thats it for IABs. Keep reading though since it gave me problems.



Since this is specific to a GS-R, I had to do the following:

1 - Ran 4 wires (It should have been 3) from the ecu area to the passenger side shock tower
2 - Plugged in the GS-R Bay Wiring harness into my LS shock tower harness
3 - Disconnected VTEC sol, VTEC Pressure, and Knock sensor, and found where they go to on the shock tower harness
4 - The LS side was EMPTY (for the appropriate pins), which makes sense since LS harnesses didn't have these wires, and the GS-R side was de-pinned and sliced into my wires
5 - I ran the wires to the appropriate ECU pinouts
6 - Don't forget the vtec pressure switch needs to be grounded, anywhere on the motor is fine. I used the thermostat housing.*


I recommend actually going to the junkyard, cutting out an ECU harness, and using the pins and pinning the ecu PROPERLY! It is very very good in the longrun, and the tools consist of

a) A thin, pointy pic (your friend's ***** will do, J/K )
b) A battery-powered soldering gun from any parts store, they run for about 20$ and usually include solder


Now, here is where it gets tricky. IAB solenoid, which re-directs airflow at 5800 and gives you that massive power jolt, was not working for me.


COMMON MYTH # 2

Many people with GS-Rs say that 'vtec kicks in at 5800'. This is incorrect. VTEC is barely audible on GS-Rs, and it engages at 4500. IABs will open at 5800 and this is what gives you the notable KICK. They were not working for me for a LONG time. This only applies to stock, 2stage, GS-R manifolds.

The simple solution I read everywhere was to take pin a20 on the ecu, and re-direct it to pin a17.

I did all of the above, and when I hit VTEC, I got 4 codes. VTEC Solenoid, VTEC Pressure, Knock Sensor and Coolant Temp. It ended up being a bad ECU so I just chucked it.


I got a new ecu and I was still getting the code. It turns out, that, you actually NEED TO GROUND THE VTEC PRESSURE SWITCH!!!!!!!!!!!!!



This image is almost accurate. Ignore the pink wire since it doesn't go into the same shock tower connector as the others, but the ground wire is accurate.

So after grounding the vtec pressure switch, It did indeed work, but the IAB solenoid was NOT getting a vacuum on idle.


THE AMAZING IAB SOLUTION FOR THOSE OF YOU WHO ARE READING THIS THREAD FOR THIS ANSWER ONLY

OBD1 and OBD2 GS-R motors have different wiring schematics. The IAB Solenoid valve, should send a vacuum to the IAB Plunger (Located at the driver side of the manifold, you can open/close it with you finger sort of like the throttle body)

Here is a pic from above, it is the mushroom shaped thing on the very left with a vacuum hose going into it. LIKE I SAID, this should get vacuum at IDLE




- If you are not receiving vacuum it could be one of many things:


1 - Your solenoid is bad (Remove the black box, apply 12 volts, listen for click, if you hear it, it works)
2 - Your 1-way check valve is plugged (pull out the little white one way valve, blow in it from both sides, it should work with one only)


3 - The IAB solenoid is receiving the wrong wiring schematic!

The IAB consists of two wires. One wire is PINK (goes from IAB Solenoid to the ECU), and one wire is BLACK. Now, for OBD2 models, this black wire was a shared GROUND among many sensors. BUT! For OBD1 models, this was 12volts!!!!!! So, I was using an OBD2 harness, with an OBD1 ecu, therefore It was being supplied with ground instead of 12 volts.

The solution is to cut the black wire at the IAB Solenoid plug, and splice it into any 12v source from the PGM-FI main relay (Injectors, EVAP solenoid, Crank sensor, etc, anything 12v). Make sure that the harness side of the black wire gets taped up because it needs to remain as a shared ground. Dont just splice in 12 volts, you actually have to cut it at the solenoid because the ground still needs to remain there for many other sensors, its ONLY THE IAB THAT DIFFERS.

Now, when you cut it, the black wire leaving the IAB Solenoid needs to be 12v. Some people use injectors, some people use Crank Fluctuation sensor. Its up to you at this point.


After I did this, my IABs didnt work since the second ECU was a chipped p28 for a skunk2 manifold. I just swapped ecus to a stock, p72 and it worked.

If you have tried all of the above, and it still isnt working, find a friend with working IABs and use his ECU, or pm/post here!


COMMON MYTH # 3


GS-R is a direct swap! Read below for a detailed swap list

This isn't true!!!!!!



Even if you are in the same OBD window, there are a few things that don't line up. One of the heater-core hoses didn't line up perfectly with one of my coolant galleys. It is slightly kinked. I put a clamp on there and it is working, but this is something that worries me.

Also, the charcoal canister on obd1 motors might be different from obd2s since I have 1 or 2 vacuum hoses laying around from the canister. I am going to check some diagrams and update this later.

The throttle cable will need to be out of a GS-R. Make sure you have the bracket as well since the LS cable is different in design.

OBD1 GS-R motor in an OBD2 will be a nightmare. I would highly discourage this swap unless you convert to OBD1, since the oil pump will be missing a sensor.


That is all! I will clean this up since I wrote it all in one go! Thanks for reading! :D



KEYWORDS TO HELP YOU FIND THIS THREAD:

obd2 gsr swap no iab
IABs arent working
swapping obd2 gsr into obd1 ls