Working on a swap... it's an H22A4 into a 96' Civic DX and I ran into a few issues... beforehand - the swap was installed by the previous owner and I didn't like some of the wiring and fuel lines being bent and whatnot... so I replaced the following:

- Fuel rail, filter, and regulator with AEM components, -6AN inline filter and braided hoses
- Engine harness was changed to a 96-98 EX harness that I extended the necessary wires for the alternator
- Originally the car had no IACV and all I did was add on the Rosko Racing IACV relocator plate... but just blocked it off for now - maybe a possible slight vacuum leak
- Brand new fan switch, thermostat, and radiator
- Brand new starter, alternator, and battery

Issues so far:
Speedometer not working (used to)
Fans not kicking on (turns on when I jump the connector though)
Bogs while driving at partial throttle (10% or so)
Battery doesn't seem to be charging... the car will jump start and run fine, but then after a few miles it'll lose its charge, the interior lights get dim, and the tachometer stops reading (weird)
Also my heat doesn't work anymore...

Tried bleeding the coolant for like 30-40 minutes and nothing ever happened... I don't know if the fans ever worked since the car was purchased in winter time... but everything else worked fine and the car drove somewhat normally. It's running a chipped P28 that came with the car... currently has a CEL but I haven't checked it since I can't get the car to run long enough to make it to the parts store lol

 

A crappy alternator can cause a lot of unusual symptoms. Test it FIRST before anything else.

Next, pull the god-damned codes and fix them. It's like asking a doctor over the phone why you don't feel well and NOT MENTIONING the 4 gaping bullet holes in your stomach. No amount of wisdom from this forum will help you if your codes indicate a problem we can't see.

If the bogging isnt' from low voltage or something else clearly shown by the CEL code, it could be from the lack of a pulse damper on the fuel rail. Aftermarket fuel rails & filters shouldn't be used without an aftermarket pulse damper or without a top-shelf regulator.

After that, you'll want to get a basic AFR street tune at the very least. I've seen no-name chips running motors far worse than a stock map. Someone even posted a vid (since removed) showing H22 chips against a basic dyno tune. Most chips lost power over the OEM map, at least two of them ran the motor so rich/lean it would have ruined it.

Lastly, the heat issue is probably from a stuck-open thermostat. Genuine Honda t-stats are CHEAP, and worth it. No matter what other idiots say, you don't need a low temp t-stat. That could be the reason you can't get heat and the fan won't turn on.

 

My speedometer and alt just quit too, I bet it's the same problem. Typically you can look and see if fuse 1 or 15 are blown, in my case they are not because of the crappy wiring.

I couldn't find any blown fuses for those two, so I'm going to re-run the wires.

You need a key-on hot wire, these are usually black-yellow in the harness. Splice it into the black-yellow on the alt plug, and do the same with the yellow wire on the speed sensor.

Bet that's your bitch.

 

You have made a common 6G swap mistake... using an EX engine harness in a DX chassis. You MUST use the original engine harness and modify it (add wires and lengthen/shorten what already exists) to meet the requirements of your new engine. Examining the chassis crossover plug (it's green near the ECU plugs) shows you why: when plugged together, wires don't match across it. This means that some items go to nowhere and others get the wrong signals. If the original harness has been modified too much to repair, find another one from the same YEAR AND TRIM LEVEL as your chassis. Compare the crossover plug first... if all wires match up (quantity and position, not color), you can use it.

As for your ECU... a "chipped" program could be all talk and no substance... find a local tuner and tell them your needs and get them to produce a basemap that fits your requirements.

 

I had the same problem in my ek3.

the reason after 2 hours searching for problems in the engineroom:

a fuse was dead. i believe, the alternator fuse or something like that. don't know, but it ran after changing that fuse. check all the fuses!

 

Alrighty... to not leave people hanging and potentially help out anyone else who runs into my issues with the same swap...

1) My alternator fuse was popped, replaced it with a new one and it began running way better. Alleviated my problems of the speedo not working and it losing a charge and whatnot - also found that my battery fuse was actually a 50A instead of 80A, switched that and the alt. fuse and no issues since.
2) I replaced my 'chipped p28' with my Hondata S300 V1 unit with a basemap supplied by Phearable.net. Immediately the car ran way better and also the bogging issue had gone away. Idles fine and I was able to check my MIL codes. All I have a code for is an IAT sensor right now, once that is squared away everything should be golden.
3) Cooling issues - haven't really addressed the problem since, I have the plug jumped right now so the fan is always running. My theory is that my autozone thermostat isn't opening or I have a huge air bubble somewhere. Engine temperatures haven't been soaring and no signs of coolant leaks or anything since... I even drove it to the track and did almost 10-12 passes in the 1/4 without any issues. I've also narrowed down the no-heat issue to a broken on/off switch in the engine bay to allow coolant to pass through, the lever to switch it has broken completely.

next step is to source a shorter alt. belt since the one i have is causing the alternator pulley to hit my DR headlight and also rebleed the coolant system.

Also to respond to this... I haven't really read/seen anything about using an EX harness in a DX/CX shell being an issue. It is usually an easier route as mentioned in multiple engine sway guides to use when not wanting to add/extend any wires to the existing harness... now switching between chassis years of 96-98 to 99-00 is when you would run into problems... I've done a couple of swaps now myself and every "EK" i've worked on we have opted to swap in a VTEC harness just because its easier... I've never heard of issues with the cross over wire tho...

 

I can see this issue between OBD2A and OBD2B, but between a DX and EX harness? I have a 98 LX sedan, and I am running a 96-98 EX harness with absolutely no issues. If the DX harness is different than the LX harness, I can't see where.