Richard, Do a continuity test of the Idle Speed Microswitch. If it checks out OK the Idle Speed ECU is probably defective. DMC Joe / DeLorean Services / <dmcjoe@xxxx> Web Site: <http://www.deloreanservices.com> ---------- > From: Richard Strecker <dmc1219@xxxx> > To: News, DMC <dmcnews@xxxxxxxxxxx> > Subject: [DML] Just wondering > Date: Monday, August 23, 1999 6:46 AM > > Would a bad coil capacitor cause the tach to read about > double the actual RPM? NO! > > Could this cause a fast idle condition? NO! > The reason for the question is that a friend just purchased > a "D" and has had a problen with fast idle (12 to 1500 RPM > measured with an external tach). The tach on the dash reads > about double the measured RPM. > > He has replaced the idle control motor, coil, fuel pump, > fuel filter and several other components. The throtle cable > moves freely and the linkage doesn't seem to hang up any > place. The micro switch is operating when it should. The > frequency valve appears to be working in that you can hear > the change in frequency as the engine warms up. He has not > been able to get the dwell set due to the high idle speed. > > I have searched the back issues of the DMCnews & it looks > like he has covered most of the bases that have been tried > before. > > He's getting rather discouraged & I'm about out of ideas. > ANY suggestions would be appreciated (well, almost any). > > > Richard