Phillippe; This sounds to me that your fuel pump is not keeping up with the demand of your engine. If you have a fuel filter, change it. If you don't, try a different fuel pump. Dick Benjamin ----- Original Message ----- From: Philippe COURANT <accf_clb@xxxxxxxxxxxxxxxx> To: IML Imperial Mailing List <mailing-list@xxxxxxxxxxxxxxxx>; Fwdlk <L-FORWARDLOOK@xxxxxxxxxxxxx> Sent: Sunday, February 10, 2002 10:34 AM Subject: IML: curious "cruise control" on my '57 > Hi, > Today the weather was fine so i made a short trip (40 miles) with > my '57. As i drive the car on straight road with few traffic, i > want to see if the car goes fast. So i put a heavy pressure on > the right pedal !! Speed increase fastly, 40, 50 , 60 mph but at > 65 mph a curious thing appears: the engine suddently slows down > until speed return to 60 mph. The same feeling as if i've > released a little the gas pedal... Then (as i don't release the > pedal) the speed increases again until 65 mph then slows down, > then increases etc.. The gas pedal was not on the floor but there > was no effect if i pushed it to floor, no engine rev. > modification, like an automatic (and non adjustable !) cruise > control !! > I release the pedal until speed slows to 55 mph then i smash the > pedal to floor: the car rushs very fastly .. until i reach 65 mph > !! So impossible to exceed this speed, the engine speed decreases > every time..( except in a small downhill where the "max. speed" > is 70 mph). > I suspect two things: a vacuum advance problem (or a mechanical > advance problem) or a vacuum problem on secondary barrels of the > carb. But i "feel" the opening of the secondary when i smashed > the pedal below 65 mph !! > Advance was set to 12° btdc some weeks ago (no test at high speed > since), because before the setting was too high (20° !!) but car > ran fine with this high advance (and exceed 65 mph ..). > Any advises ? > > -- > Philippe COURANT (Pau, France) > Imperial 57 Crown convertible > Buick 58 Roadmaster sedan > > - American Car Club de France (ACCF) : http://www.accf.com > > - Chrysler Imperial France : http://www.ifrance.com/c-i-f > > - Cadillac " Standard of Excellence " : > http://www.ifrance.com/accf-cad > > - SportsCars : http://www.ifrance.com/accf-sprtcar > > > >