My friend has a 94 gsr w/ a JRSC and his idle goes up to like 3000 then back down to like 1000, it keeps doing it.....need some help here! it has rc 310cc and the upgrade kit on it. Also with the fmu do you still need to hook up a vaccum line to the stock fuel pressure regulator?

 

sounds like a vacuum leak. keep the vacuum line plugged into the stock fpr, otherwise it will be closed all the time and your FP will be high off boost (on boost it won't matter b/c the other FMU will be more restrictive)