It may be superfluously, but even my Pontiac Transport from 1996 does prime when the ignition is turned on. I guess there are many car that have fuel pumps working that way. Welmoed. --- In dmcnews@xxxxxxxxxxxxxxx, "Steve" <p2freak@...> wrote: > > Group. > > The circuit in Dave's drawing is a one shot monostable circuit. > Meaning as soon as there's power, the output to relay coil is > energized, closing the contacts. So the RPM relay is set to pre- prime > before there's a tach signal. > > Don't know if the new relays have the same schematic. > > > Steve > VIN#04421 > > --- In dmcnews@xxxxxxxxxxxxxxx, doctorDHD@ wrote: > > > > > > > > For Dave S and anyone else interested... I posted the schematic of > the RPM > > relay in the files section, back in July 2005. It's still there. Now > > someone with intimate knowledge of how a 555 timer works, will need > to decide if it > > is supposed to prime or not. > > > > > > 7b. Re: RPM relay (was I think my fuel pump...) > > Posted by: "Dave Swingle" swingle_dmc@ daveswingle2 > > Date: Tue May 1, 2007 11:36 am ((PDT)) > > > > > 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/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> 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/