Car only starts with OBD2 scanner attached - Car Forums and Automotive Chat

Okay fellas.. I got a major problem i cant seem to figure out.. My friends 2004 civic need a rebuild due to a spun rod bearing..okay i finished the rebuild and reinstalled everything..i go to start it and it starts right up ...it runs for about 45secs to a min then shuts off...i go to restart it and it just turns over..now while trying to restart it...im hearing the relays behind the glove box clicking away like crazy...so i connect my obd2 scanner to see if i can pull any codes..no codes pop up..so then i try to start it while the scanner is still connected and voila....It starts and idles like a champ...now while it is running i decide to disconnect the scanner and it dies..go to restart it ...it wont start...reconnect the scanner and once again it starts no problem...does anybody have any possible reason for this??? i did some research and cant find anything...thanks