B20Noobie

hey everybody i am a new user here but i have visited this site among others many times for my research. so ill do my best to give ALL of the information and steps taht i have gone through prior to asking for help here.

about 3 months ago i bought a crx shell completely stripped of everything for a project. i then bought a integra that had a b20 frankenstein swap already done. drove it home and the engine ran great!. no problems except for a check engine light. i did NOT check the code before the swap. just plucked the engine out and plopped it in the crx. everything went smoothly, untill i try to start the car and notice that i have a few new problems.

the car will die at startup. or i can keep trying and it will eventually start(sometimes). wen it does start, i can give it some throttle and it will die, or i can wait however long untill the cel comes on and then i can give it gas and the engine will rev fine, sounds fine too. wen i checked the ecu code it is giving me 3,4, and 5 all randomly. most of the time its 3 and 5. sometimes its just 5 and sometimes its just 4.

so those codes i figured are for the map sensor, so i re checked idk how many times the vacuum lines to make sure they are al routed right, which they are. the only lines i have discontected are the lines that go from the intake mani to the intake piping. (btw this is a ls integra head). ive unplugged the map sensor to help the engine start, ive tried swapping the plugs from the map and the iacv, ive tried messing with those two random lines for the intake piping (which im pretty sure wouldnt throw a map sensor code anyways) just to no avail at all.

and now the part that persuaded me to start a thread: the brake lights are stuck on even with the key not in. the rear brake lights not dash brake light. this problem was not there yesterday nor wen i arived again today to start troubleshooting a bit more.
this whole thing has got me really stumped and i would really appreciate any help/ advice anyone has to offer. im new to the honda game and this is my first swap with little experience and ive done it all so far all by myself.

B20Noobie

ive also checked all the grounds i know of: the two under the dash. ecu ground on thermo housing, and even added a ground on valve cover additional to the one that was already there.