K I just pulled out my buddies tired LS and put in a B20B. its in a 4 door civic, the guy he bought it from put a complete 90-91 Integra wiring harness in it, for the entire car. Why he did that is beyond me. Well anyway the swap went fine. When I drove it the car is fast till about 3k rpm then the intake gets ridiculously loud and loses hp and some times it feels like a slow rev limiter at about 6k. so I believe its timing but its something I have never seen before, first off the motor was set at TDC. when the distributor is where it should be it idles perfect. But when I through a timing light on the motor and moved the distributor so the crank pulley showed TDC, it had a rough idle. It also sputtered and then revs when I pulled the throttle back. Everything worked fine on the ls. And there’s no mill (check engine). A few other things we put ls cams in it. It has noligy hot wires don’t know if the grounds on the wires could do anything and were using the b20 crank pulley. Has any one ever experienced this before????

The distributor looked like this when the crank pully read TDC.