This same thing has happened to many of us. Mine did it twice and I don't use any fuel additive. Those O-rings are swelling with today's fuel. Viton does not swell. I ran a swell test with Viton and buna-N. --- In dmcnews@xxxxxxxxxxxxxxx, "John Marconi" <giantscorner@...> wrote: > > All > > Does anyone have knowledge of Fuel Injector Cleaner additive possibly damaging the O-rings on the Primary Fuel Pressure Regulator. > > A few months ago I fixed a warm start problem by replacing the 2 primary fuel pressure regulator O-rings. The smaller O-ring had a small chunk missing which apparently was affecting my rest pressure. Well, the problem returned and I found the same thing, a small chunk missing from the smaller O-ring. The only thing I can think of is I put in some Fuel injector additive about a month ago. > > Some side info to ponder. I did not use anything to lubricate the O-rings when istalling, I was concerned with it causing a clog down the line and felt the fuel should act as a natural lubricant when installing. > > Could there be a metal burr or something in the fuel distributor that is damaging the O-ring upon installation. > > Thanks > > John Marconi > VIN 3760 > ------------------------------------ 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/dmcnewsYahoo! 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/