Hi everyone! First off and foremost. I’m new to the Honda scene. And I’m looking to get lots of my questions, answered for my car.

I own a 1996 Honda Civic DX with a GSR swap. The motor was out of a crashed 2000 integra GSR (engine/transmission) matching vins. Swap was done by the previous owner and the engine had a rod knock. Upon further inspection, I brought it to a friends’ performance shop and rod #3 was destroyed along with the crankshaft and badly worn bearings.

I bought another GSR engine, unknown miles and unknown year integra it was out of or previous swap. It cranked by hand smoothly and had the shop swapped it in. Car would turn but wouldn’t start.

Car’s wiring harness had a different Crank Shaft Position Sensor (CPS) and the engine that had the sensor was a different plug. I recently wired in the new CPS connector that I bought from rock auto. Car also wouldn’t start. I also do not have a o2 downstream plugged in and I’m not sure if you can start the car with that being by passed or not plugged in.

Either way, the swap is bad. I’m looking for answers to get it going. I’m not in a rush by any means, as I’m busy and currently in school.

I also have misc hoses that are unplugged and mysteriously plugged into. Please if anyone has the time to help, please let me know with pictures of diagrams and other sorts of things I should know.

 

So does the car crank over but it doesnt start?

 

Yes, the car cranks over and idk why it’s not starting. Got new NGK specific plugs for it yesterday (3/23) and still has hesitation to start.

Me and my brother got it to start but it sometimes dies off. The previous owner said the car sat a couple of years and old fuel is still mixed, I’m not sure if I’ll be needing fresh fuel and to see if that may be a culprit? Or something else? I’m not sure. Loss at this point. Please get back to me ASAP. I’d like the car to start every time it cranks the first time around.

 

yes it needs fresh fuel. diagnose your dizzy. what ecu?

 

Yes, I’ll try new fuel once this covid mess is situated.

i haven’t diagnosed my dizzy, but I was told to check the timing on it? Wasn’t sure how. But google and YouTube is my friend of course. Running a OBD2 P72 GSR ecu

 

obd2 .......what....

 

A 1996 Civic DX and a 2000 Integra GSR have different style ECU plugs... do you have an OBD-2A -> OBD-2B adapter harness AND have you disabled the immobilizer inside the ECU ?

 

FYI, you would be better off finding a '96-98 Integra ECU instead of trying to use the '00 P72 ECU... your life will be much easier.

 

That’s a lot of input there. I appreciate it. I will have to check and do more research. The ECU plugs in just fine but I’m not sure why it’s still not starting. I also don’t know if it’s been immobilized. I’ll have to do more research.

 

straight up dodge the question...oh well...

 

oops, sorry. I don’t really know. Just know it’s a p72 ecu and obd2. Don’t know if it’s A or B haha.

 

If it is in fact a 2000 GSR that the engine and ECU came out of, well... then you know the answer.
It shouldn't plug into a '96-98 Civic engine harness, but if it does, this would suggest that either the engine harness is actually a '99-00 or the ECU is not from a '00 GSR. Now, if the engine harness does plug into the ECU... and it IS a '00 GSR ECU, then the immobilizer is inhibiting engine function, but the OP wouldn't know it because the Civic instrument cluster doesn't have a green blinking key displaying the immobilizer interference. A pre-'00 P72 eliminates the immobilizer issue, and if it plugs into the OP's car, it should start up.

OP, have you tried to start the engine with your original DX ECU ?

 

Post the part number of the ECU please. It will be on the white sticker found on the side of the ECU... and if that is missing, it can also be found on the sticker affixed to the top edge of the grey ECU plug socket under the lid. The part number will be 37820-P72-XXX.

Now, help us help you identify your ECU and engine harness.

1) Does your original DX Civic ECU plug into the engine harness plugs that are in your car now ?
2) If it does, make a note as to the order of the plugs and where the open slot between plugs is found.
3) Now, does your P72 ECU plug into the exact same locations with the same open slot and the same plugs used ?

 

Sorry, I didn't mean to scuffle any controversy over my newbie-ness as this is my first swapped car and is a project for school purposes.
@JRCivic1 Yes, you sir guessed it correct. The motor and trans are matching vins as well as the GSR ECU and possibly the harness? I am not completely sure, but the ECU plugs in just fine, as for the plugs on the wiring harness, it plugs in on the engine itself but, yes everything is in place and should plug in as is. Note, that I bought another GSR engine due to when I bought the swapped car, the previous bottom end of the GSR was knocking badly to find out the crankshaft and rod #3 went out. So I bought another GSR long block replacement. Also, note that I am a full time student and I didn't diagnose it at the time, so I had my cousins who owned a shop install it for me.

Soon to be told that, the CPS sensor two pin plug was different to the CPS (Crankshaft Position Sensor) connector that is attached with the wiring harness. I was told to cut the connector and find a CPS gray two pin connector, I just did that, ordered the part on rock auto and soldered it back in and connected the CPS, but still wouldn't start on the first try. Wish I can provide a video of it starting and it running but there's a lot of hesitation to it. The car cranks and turns on but with lots of hesitation. Hard to put in words, but yes, it starts and runs while pumping fuel. But with lots of hesitation, Idk why. I want it to start without doing those steps of pumping and all. It is very tricky to get it started.

Also, I have an actual EM1 Si cluster that is fully working. As of now, things that I don't have connected are one or two plugs that I don't know where it goes to and just the o2 downstream that connects to the cat. I checked all grounds and they are secured, from valve cover, to tranny ground, and to thermostat. Not only that, the battery was relocated to the back of the trunk. I'm not sure if that can mess with starting the car? To me, it doesn't look professionally done and I have not yet relocated a battery myself so I wouldn't know.

Also, the car is wired in with a push to start, leaving the ignition key useless but to prime fuel only of course. I'm also not sure if that'll mess with the troubles of starting. But I will attach pictures next!

Thanks@JRCivic1 for giving me insight and help. Again, sorry to stir any controversy over my dumbness.

 

@JRCivic1 To answer your #1 question, I bought the car swapped already and was not given any of the original harness and ECU for the civic.

Questions #2 & #3. I don’t have an answer to that. Everything plugs right in on the motor, but I still have one or two connectors that I’ve seen that still needs to be connected.

note that I already started the car and it has ran but it dies on me. I will provide a video if I can.



GSR ECU

Plugs right in as of now

New long block

Old long block that had knock

CPS sensor (Gray two pin plug in)

Here’s the CPS Connector that is attached with the wiring harness, again already cut and soldered on new one and plugged it right in to the sensor. This one is black, was told all CPS connectors should be gray.

The new connector connected

 

Also, given the new long block, I was given a OEM Honda (DENSO) starter and OEM alternator. I video chatted a friend of mines and we looked it over and he said, it checked in fine, was also hard because he wasn't there to fully inspect, but he did confirm saying it looked good.

He told me to check my dizzy timing which is pushed all the way up. He said the timing should be in the middle somewhere, but it varies by how it is set up? I'm not sure. Told me to check the timing on dizzy and retard. I took off the intake and sprayed brake clean inside the throttle body, but still nothing. While video calling, I didn't catch it myself, but he said the starter might've been ticking? I'm not sure what that means, but possibly the starter going out? Not only that, My car relies a lot on the battery. This is my second battery going out. But that's probably me not recharging them both.

Has coolant, has fresh oil, needs fresh fuel. The car sat for a couple years I wanna say, and I have not added fresh fuel. Old fuel could possibly be a culprit? correct me if I am wrong. My buddy told me I didn't need it. As long fuel is being primed and pumped to be able tot turn the car over in hopes of it running.

Kind of loss at this point.

 

Glad you posted some pics. This is very helpful. How about posting some pictures of the engine bay as it is now with some close up pics of the wiring plugs and colors of the MAP, TPS, IAT, fuel injectors and engine coolant temp. Also, a close up pic of where the fuel feed line connects to the fuel rail could be telling.

As for tony 2018... he is a veteran here and he can take a poke just as good as he gives 'em. No apology is necessary. I wasn't giving him any static... just reminding him that you had already answered his question... you just didn't know it. I guess sometimes things "sound" differently in a 2D world, but I am pretty sure he and I are good.

 

I also want to note, with this new long block that was installed, It cranked smoothly by hand and the timing was out of place which I had the shop correct the timing, I have not fully checked the timing since. Was wondering if I should check there first and figure why it's not starting? Lots of theories to what it is. But again, any help and more insight is appreciated as I go on tackling the problem to what it could be.

Last resort would be when I'm done with my spring semester for school, to pull the motor and source the wiring issues that it may have and to see what harness I am actually running. I use to own a parts car; a 99 civic 5 speed manual EX coupe, but the CPS on the d16 was a three pin plug, totally different in comparison to the GSR two pin CPS connector. Thus why, I think everything in this swap was out of an 00 GSR integra. I am just planning on running NA, no boost applications just yet. I want to run the car as stock as possible and enjoy it for what it is now, then boost later down the road with a different ECU etc.

I also replaced fuel line that was connected on the 99 Civic EX coupe 5 speed manual, the fuel line the connects to the fuel filter to fuel rail. I replaced the GSR one because I couldn't find a exact part number and so I replaced it with the 99 Civic EX coupe Fuel line. The GSR was badly bulged and rusty. I am also not sure if this will cause a restriction somewhere in the fuel system? Didn't know if the part was interchangeable. Installed it as is and never looked back.

 

This is why I asked for the photo of the close up of the fuel inlet end of the fuel rail. The fuel lines are NOT interchangeable and will in fact be a serious fuel restriction. Remove the 22mm fuel pulse dampener bolt, make sure the small outer washer isn't crushed into the face of the pulse dampener (gently remove it if it is) and re install the old rusty/bulgy Integra hose. The old fuel isn't necessarily an issue to keep it from starting unless it is full of water. Old gas burns just fine... your friend was right. I noticed in some of your photos above that your CKF plug is connected to a black/yellow and a light green wire... these are NOT the CKF wires in that engine harness, and thus, plugged into the wrong circuit. This is likely why you still have a code for the CKF sensor. Find the three wire plug that I told you. You still have a Civic harness here. It is NOT an Integra harness. It has been modified, so you will have some sorting to do.

 

Some serious help going down in here! You da man!

@TomCat39 - should this be broken out into its own thread at this point?

 

Seriously! Finally after asking around, I have more possibilities to what the problem may be. If you guys can break this thread on its own, that'll be great! I'm a newbie here so I didn't know how. I did some searching as well, but the original thread post wasn't similar to mines.

@JRCivic1 Thanks for the input a ton!! I will check later and get back to you. Wish I can do it now, but priorities for school is calling. Sorry! I'll do my absolute best to keep in touch. Please do on the other end as well.

Thanks all!

 

Sorry for being late to the party, I was at work and never got around to check the thread til now. Looks like youve got some great help already but Ill post my notes of what I did with my GSR swap also. Im treating my swap sorta like a scientific research so I tried to document all my steps as much as I can but I may have left a few details here and there. NOTE THIS IS A 99 Integra GSR (obd2A) swap to 99 Civic EX (obd2B) THAT I WAS TRYING TO GET READY FOR C.A.R.B INSPECTION AND TESTING so some of these steps may not apply to you if you dont live in California but it may help with diagnosing your swap. But the main thing Im curious about is if you have switched the fuel pump relay pins yet from pin location A16 to A15 because the fuel pump is pinned differently for the Integra. And reading through your replies to their questions, a problem may exist too with the push button ignition if that is not wired correctly. The ECU you have right now (P72-A03) is the correct ECU. 96-99 Integra GSR’s are OBD2a which are the same as 96-98 EK’s thus explains why it plugs in no problem. You dont have to worry about the immobilizer at all since those are for 00-01 GSR’s (P72-A05). Something I noticed on OBD2a 96-98 Civic’s is also that their engine wiring harnesses are a 2-piece design, meaning you can disconnect the engine harness connectors separate from the under dash/interior harness connectors near the battery in the engine compartment. Instead of cutting and splicing certain connectors here and there, you couldve just used the original 96-99 OBD2a GSR engine harness and connected it to the 96-98 OBD2a interior/cabin harness, but adding maybe some wires/pins for the knock sensor and the IAB’s on the cabin harness side. Wouldve made life easier and would be a direct plug and play set up. But in any case, I hope my information can help you out as well. Theres still a lot I need to learn also. I just swapped my GSR in my Civic back in Aug of 2017, and passed C.A.R.B inspection the second time around (first time was Feb 2019) in March of 2019. Just to give you a quick background/purpose on my build, my purpose for my build is to be a 200whp street legal, capable, daliy driver that will last me til I get old haha. Im trying to keep things real simple and still easy when in comes to maintenance. Im trying to make this car last as long as I can but still have fun in the canyon/track corners and chase down higher performance cars. My next steps are to dyno my car currently as it sits completely stock so I know my baseline numbers and work my way up from there. Some of it is still fresh in my mind so let me know if I can help with anything else!
(please see screen shots below for notes)

 

@JRCivic1 I have found the gray CPS sensor connector. I will list some pictures of it and the color of the wires are correct. The harness is a bit short and won't reach the CPS plug in on the GSR engine. Would I have to solder again?

As well, I threw out my rusty and bulging fuel line. It was really bad. It leaked fuel on both ends of where the filter and the end of the fuel rail was. I'll source one locally if anyone is parting out their GSR. Would any Integra fuel line hose work? or just the GSR? Again, I will attach photos.

Also, mentioning that the wire that I had mistakenly misplace for the CPS, do you happen to know what or where that plugs into? I have two other connectors that are the same that plugs into possibly somewhere or nowhere?

 

Wow, @JDMkid29 This was very helpful! I finally understand why it plugs and play sorta haha. I will have to check the fuel pump relay pins to see if it was moved from A16 to A15. I didn't know about that myself, thanks for clarifying about that.

Also you mentioned, "And reading through your replies to their questions, a problem may exist too with the push button ignition if that is not wired correctly.". To what extent would that cause problem wise? I was tinkering around with the starter and there was two connectors, one unplugged and one plugged into the starter which was the push to start. I believe the other taped up plug in was if I wanted to revert back to ignition starting? I'm not sure and I didn't test it out. But I'll take some pictures and show you how the previous owner had did it.

Quoting what you said here, "Something I noticed on OBD2a 96-98 Civic’s is also that their engine wiring harnesses are a 2-piece design, meaning you can disconnect the engine harness connectors separate from the under dash/interior harness connectors near the battery in the engine compartment. Instead of cutting and splicing certain connectors here and there, you couldve just used the original 96-99 OBD2a GSR engine harness and connected it to the 96-98 OBD2a interior/cabin harness, but adding maybe some wires/pins for the knock sensor and the IAB’s on the cabin harness side. Wouldve made life easier and would be a direct plug and play set up."

^ do I need to add anything else? Since I found the 3-pin CPS connector, I now know that I have a 96 dx engine harness and not a GSR engine harness. Can you explain more here? Sorry, I'm a noob. Those terms are too big for me haha.

But yes, this has definitely cleared some problems! I appreciate it a lot!

 

Please ignore what this rookie stated in bold italic above... it is COMPLETELY wrong and could be confusing to people who read this... just as it has pulled you in the incorrect direction. All 1996-2000 USDM Honda Civic's have an engine harness that is essentially one piece... from engine bay sensors/devices to the ECU. There are a couple of chassis connections found on the driver's side of the engine harness, but it does NOT connect to the chassis harness on the passenger side of the vehicle like '92-95 Civics or ''94-01 Integras.