Originally Posted by elsabor67
From experience (just went thru this) I would recommend that you find the same ecu for your car(last numbers 153 or 173). Connect the test ecu and if your rpm's drop to normal, swap your ecu. That was the way I found out mine was bad. Before you do that check your vaccum lines and lines. Good luck.
where did you get the last numbers 153 or 173. under what year E30 did you see it?
like i said hoses look fine, i have a little oil leak from my valve cover gasket, i don't know how much can that contribute to the high rpm.