I recently purcheased a chipped p28 ecu for my gsr/itr setup. when i installed the ecu i removed the negative battery cable and removed the backup fuse then installed the ecu. i conencted the fuse then the neg cable then tried to start the car. it didnt start. i cranked it again and held the gas. it started but the main relay started clicking like MAD. and it would misfire and shut off. i removed the p28 and tried my p72 and it started fine. What could cause this problem a bad ecu? or maybe the chip in the ecu? thanks in advance

 

What map is on the chipped p28?

 

also are you running a jumper harness with the ecu...what year gsr??? ob1..ob2....

 

sorry using a mugen chipped obd p28 and i have a 94 gsr,

 

..hmmm knock sensor problem,? any codes?>