Thanks. The idle RPMs (750 vs 850) were estimated based on watching the tach thru the back window, not with any fancy test equipment. Strange thing to us was the difference between the two cars, one going to 1200 and one (mine) going to around 900 by flipping the microswitch. I did notice, though that it was impossible to make my engine run at, say, 1000 rpm with the gas pedal, it was either above or below. BTW - these two cars were within about 400 VIN of each other, both 10/81 build. So - I guess the other car has a 1200 rpm ECU and mine has 900. Any idea when the spec changed? I'll bet it was 10/81 or one of these has been changed. My car is the slightly later build date of the two. Thanks!! Dave --- In dmcnews@xxxxxxxxxxx, "DMC Joe" <dmcjoe@xxxx> wrote: > Dave, > > There are two versions of the idle speed ECU both are set for 750 +/- 50 RPM when switched on and 900 and 1200 RPM when switched off. Although the 1200 RPM sounds high the effect will null out as soon as a load is placed on the engine. > > BTW; your idle speed should be 750 RPM not 850. > > > ----- Original Message ----- > From: Dave Swingle > To> Subject: [DML] Idle_Off-idle problem > > either idle at 850 rpm (normal) or, as you tip-in the throttle, jump > immediately to about 1200