Airborne29th

Ok, so me and my buddy did the b20 swap in my EG this weekend, and all went well. Only snag we had was a temporary exhaust solution. We used an older b series header because the b20 exhaust manny that was on the motor when I got it was only the top half, so we connected up the b series header and then went to attach it to the cat, and the bolt holes would not line up, so we decided to rotate the cat one turn to make the bolt holes line up and everything connected fine. Well when we started it up it idled really rough, and threw a cel. Pulled the codes and found it to be the IACV and the IAT connectors were swapped, changed those and that fixed that issue but still a rough idle.

So we decided to try and take it down the road and it drove ok, but seemed like it was bogging down and had no low end power at all. It took it a while to fully rev up.. My D15 accelerated quicker than this did! haha. Ok, so we got back to the garage and were checking for leaks and I looked underneath and saw the Cat GLOWING RED HOT!, immediately we shut it down and checked everything over and could not find what could be causing it. Did a little research and found it could be unburnt fuel going into the cat and burning off?

Ok, so now a little back story on what was done during the swap. The Dizzy was an OBD2 which we depinned to OBD1 connectors from the D15 dizzy, The fuel injectors were also depinned and connected up to the new OBD2 plugs. And the Alternator was depinned and swapped to the new plug. Could any of that cause an issue? I’m running a P75 stock ECU, would using the B20 injectors make it spew more fuel running the P75? I thought that the injectors from the D15 were pretty close if not the same CC. Could my Cat just be clogged for some reason, we didn’t look all the way through it when we rotated it.. I don't know why.. but it was fine before the swap...There is what looks like a burned up O2 sensor still in the Cat that we found when we rotated the cat, but we didn’t pull it out due to there would be a giant hole in it afterwards. This is long I know but I need to get it running and I don't want to drive it and melt the exhaust and blow the engine up... Also, we did drive it about 4 miles down the road after the initial drive to take it to his house and all the while it was chucking molten pieces out of the exhaust he said.. so the cat is probably gone now... HELP! haha..

Fabrik8

First of all, you're using an ECU from a smaller displacement engine, so it would tend to run slightly lean probably. You're also using slightly smaller injectors if they're from a D15. So most likely the cat is glowing because of the high exhaust temp from the lean condition. If the cat is damaged or clogged that isn't going to improve things at all...

So it sounds like you need to get the correct parts to finish your swap, and you can get that P75 chipped for the B20 (or tuned, which would be ideal).

Airborne29th

Sorry for the confusion but the injectors being used are the B20 injectors.. the only difference is they are pinned to my OBD1 wiring harness, and the P75 is what is recommended for a B20 swap, It can be run on a P75 stock just fine with no problems on it's basemap. So that should have no affect as to the mass fuel dumpage and glowing cat.
I'm going to check the timing at the cams and the distributor when i get home and check all the plugs to make sure theyre not fouled up and then onto the injectors to make sure they not just dumping fuel in or not working at all..

Fabrik8

Oh, I see. I missed that part. The P75 is not ideal, but will work close enough with the stock B20 and stock B20 injectors.

Gen_Crunchytoes

I've always heard, and read that a p75 is ideal for a b20 because its tuned to run an ls slightly rich. Please correct me if im wrong as this info came from team-integra. And they're a bunch of geniuses

Fabrik8

Like I said, it's close enough. It's an engine with different cam profiles, different intake ports, different displacement, different intake manifold, etc. So the stock tuning is not going to be the same for a LS and a B20, but it will be good enough.

Airborne29th

I agree that its not perfect but it is close enough. I figured out the issue though. Somehow we had 2 wires switch on the distributor. I swapped them back and it ran perfect. Now it throws a CEL while running though and idle's rough, when Im driving it has its power but I can feel a bit of whats like hesitation in the throttle. But when I shut the car off to check the code it clears it.. Can I do the pin cell read from the 2pin plug while its running?

Gen_Crunchytoes

Does it sound like a lopey v8 lol? If so you have the MAP and MAFA sensor plugs reversed

Airborne29th

Well the hunt continues... I was able to read the codes this morning while idling, gave a code 43 - fuel system and code 17 - VSS, which the VSS is interesting because before I did the swap my old d15 that was in it before, the speedometer did not work on it, or it did at random, no code on that one though that I ever saw.. I pulled the speedometer and checked it and checked the harness under the Intake manifold and it seems ok so I assumed it was the VSS and thought it would be fixed when I did the swap. So, i unhooked the VSS and it has some fluid in it, not sure where or how it got in there, but it seems like tranny fluid. So i blew out the connector and wiped off the plug and connected everything back up. Took it for a drive and no more CEL's for anything and the speedometer is kind of working.. but its off like 5-10 mph and is not a smooth moving needle.
I'm going to replace the guages with one with a Tach soon so thats not a big deal, I use my Phone's GPS for speed right now anyways. But its odd that the code 43 hasnt come back yet.. I just drove it about 15miles on the highway with no issues.. I do know the O2 sensor that we put in the exhaust manifold on the new motor was one we had laying around because we could not get the one out of the d15.. but still odd.. So I guess I'll keep watch because I have read that the code can come back after a few days because the ECU resets it after reading it and will throw it again if it faults twice. Any clue?


Ah, did forget to add, after the car is warmed up it does act like it wants to overheat.. the engine temp rises above halfway and I have to turn on the heater to cool it down. I think this might be attributed to the stock radiator and fan from the d15 though.. the owner before me beat it up pretty good and I had issues with the fan coming on when it should on the d15.. so looks like time for a replacement.

Airborne29th

Mine doesnt.. but my friends newly swapped b18 does kinda once it warms up lol... that could be his issue...