B20Z2 in a 1991 Civic Hatch

[Afroshark]

I bought a 1991 Civic Hatch off of a kid recently. When I bought it off the guy all he knew was that it had a motor swap done, he didn't know what else if anything else had been done all he knew was that and the fact that the newish motor had around 100k miles on it. When I bought it, the car was running super rough and rich. I am fairly new to this type of thing and was told to check my ECU and see what had been done. IF the idiot that did the swap didn't change out the ECU what are your recommendations? It seems to be a straight up swap no different heads that I can tell. No VTEC that I can see either. From the little bit of research that I have done I have found out that the B20Z2 is from a Cr-V around 99-01. The reason that I call the person an idiot is because from what little tinkering that my mechanic and I have done together we have found things half way done, ie the fuel rail and throttle body were barely attached (I could loosen the bolts by hand without tools.) There were missing clamps all over the place. A random relay laying beside the battery. I have not had a chance to check the ECU, I was told that it is located on the passenger's side behind the kick panel. Anyone know what the stock ECU would have been for the 91 so I can compare what is there to what used to be? Any help would be greatly appreciated. I will include a photo of what engine bay looks like.

 

[flashgsr]

if your obd0 a pm6 or a pr4 will work fine obd1 p06 p75 pr4 if you pull the carpet from the passenger floor the ecu will be right there you may need a size 10 mm to remove there will be a white sticker with numbers and letters lmk what they are

 

[Briansol]

yup, ecu is where the passenger's right foot would land. under the carpet. easy to get to with a couple screws. As flash says above, a bunch of ecu's could run it. The stock computer would not, without some significant changes, to run obd0 electronics. likely, you are converted to obd1 on both the ecu side and the engine components.

There's also a very good chance it has an 'ebay' chip in it or something else. So, pop open the cover and see if it has the socket and chip added in.
(good info here: https://doogielabs.com/how-to-add-a-chip-socket-into-your-chipable-ecu/ )
if it is chipped, there's really no way to know what's on it without getting a reader and figuring out what program it was in and seeing if there's any notes about what it came from. Honestly, you're better off spending money on a custom tune with a dyno or local street tune guy who can set you up.
if it's stock, you can probably find oem replacement for b20s.

 

[Afroshark]

Sorry for the long time between posts. I finally got to check the info on the ECU. I did not take the cover off to see if it has been chipped though. Here are the photos that I snapped of the ECU and the distributor cap (I had been asked about this a couple of times so I thought I would add it as well.)

 

[CAFROG]

CEL on?

Compression test?

A picture of the intake manifold and throttle body sensors may help us.

 

[Afroshark]

No lights on at all.
Compression test came back fine.
I will try to get you a picture of the intake and the TB sensors this evening or tomorrow.

 

[CAFROG]

Just to clarify....when you put the key to the "on" position...CEL comes on for 1-2 seconds and then shuts off? Just making sure the light still works.

Mechanical and electical timing within spec?

 

[Afroshark]

Here are some photos of the throttle body as requested. I have a question the tube at the top of the intake manifold the small thin one where should it go. They stuck a screw in it and left it dangling.

I will check for the CEL when we get it back together to make sure to see if it is coming on or not.

 

[Afroshark]

The smaller tube here.

 

[CAFROG]

I think it goes to your charcoal canister but I'm not totally sure. It looks like a OBD0 intake manifold and throttle body. That's good if they're off a B18A1.

Other things would be to check how things line up with the crank pulley and cam gears (mechanical timing). And check electrical timing with a timing gun. I think 16 degrees is stock. What ever it is...I'd run 2 degrees advanced.

 

[Afroshark]

I will take a look at those either later today or on my next day off, which would be Tuesday. I believe that my mechanic checked those but, I could be wrong. I have no idea where that tube would go, I can't find anywhere that is missing a connection of that size. We did find yesterday that the person that did the swap decided to just cut wires and connect random relays (ie he cut the starter wire and connected it with a SPDT relay.). He also decided that a $5 fuse was too much money so he jumped the main fuse from the battery in the main fuse box with a piece of wire.... I have a question is there anyway that I can tell if the head is the head from the CRV and not from something else? The reason that I ask is because, the gasket looks rather new on it, as well as the one between the intake manifold and the motor.

 

[Afroshark]

I think it goes to your charcoal canister but I'm not totally sure. It looks like a OBD0 intake manifold and throttle body. That's good if they're off a B18A1.

Other things would be to check how things line up with the crank pulley and cam gears (mechanical timing). And check electrical timing with a timing gun. I think 16 degrees is stock. What ever it is...I'd run 2 degrees advanced.

Does that tube have to be connected somewhere since this is not the same motor that the intake mani would normally be on? If so where would I try to find it?

 

[Afroshark]

So AllData shows that connects to the OEM intake. (the black plastic tube connecting to the TB). Since I am running an aftermarket Intake do I just disregard that tube or do I need to try to figure out a way to connect it to the intake? The part that it is connected to in the photo is the Air Boost Valve so I am assuming that the tube is pulling fresh air in from the intake. I could be wrong though.

 

[CAFROG]

Not sure what you are asking. I think the small tube goes from that vacuum sensor to the evap purge sensor or to the charcoal canister. I think you have a B18A1 IM but I'm not sure. It's OEM for sure. The bigger tube on that sensor goes to the top of the manifold near the throttle body. Get an electronic copy of a Helm Manual for a OBD0 Integra. Don't accidentally get one for a 92-93 OBD1 Intake.

Check the Intake Manifold and Throttle Body at hondapartsunlimited.com They have tons of diagram pictures so you can narrow down what you have. I looked under a 1990 Integra 5-speed LS. The manifold looks like yours.

 

[Afroshark]

Here is the photo from Alldata, I was wondering if I should revert to a stock intake pipe so that I could make sure that tube is connected of I should fabricate a connector for the aftermarket that I already have. The 3rd option would be leaving it capped..