The reason they should be closed is because in the trim that our PRV is in, the idle speed motor electrically controls idle speed, where as other applications of the PRV do not have this device and would then use the 3 brass screws. The one screw is what sets how much air goes past the throttle plate at idle while the other two are for balancing each side of the engine if need be. That's why the screws should be closed. If they aren't, the idle speed motor cannot do its job of properly metering air at idle speed. If your car runs WORSE with the screws closed down, well that's because someone thought they should be used and they messed a bunch of other stuff up while compensating for letting air through which THEN would mean that car was never set up and running right in the first place. Andy >>>>>>>>>>>>>>>>>> In a message dated 2/12/2006 3:24:54 P.M. Central Standard Time, PRC1216@xxxxxxx writes: My guess would be to tighten them all down. I'm sure someone who is more experienced in the field can elaborate on why. In any case, tightening them down had no effect or change on my car. -Patrick C. 1880 Fargo, ND 1982 DeLorean DMC12 VIN 11596 [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/