My 260E has recently started displaying an idling problem when first started. It starts easily, idles a few seconds at 500-700 rpm,then races to 2000 rpm,then back to 500.It repeats this for four or five cycles, then settles down to normal(5-6 hundred rpm). A local shop charged $75 for diagnosis-consisting as far as I could determine of removing the air filter and breathing on the under side-then they quoted a charge of $850 to fix it by replacing the 'throttle position sensor'. Is this a reasonable diagnosis and estimate?
Where can I get a good repair manual for the '87 260E?