Volvo Repair: 92 Volvo 240 stalls at idle, vacuum leak, volvo 240

Question
Responding to your 9/23/05 article about an '88 Volvo 240--Might his throttle switch be erratic?

My '92 (206K miles) Volvo 240 runs beautifully except when idling in warm weather.  Wants to run slow and stall.  Really doesn't like me to shift in or out of Park.  Problem is intermittent.  Problem gradually turning up more often.

My mechanic checked/serviced vacuum, air mass sensor, EGR (California!), throttle body, throttle switch (set the switch).  Fresh fuel pump, plugs, plug wires, distrib. cap.

Cannot hear consistent click from throttle switch, when using stethoscope.  Does this part ever wear out, or get marginal (springs weakening, contacts corrupted, etc.)?

Thanks!  
Mark

Answer
Hi Mark,
     Rarely does throttle switch fail...
       you also have an electronic idle stabilizer...on the l/s of engine...in middle of block...hoses attached..next time it gets funny...rap this item with a metal pipe...they get sticky...
       Very old Fuel injectors will dribble instead of spraying...hence no idle...
        get 2ft piece of 5/8 in heater hose...put end to ear...other end near misc locations near intake and beneath it...if there is a vacuum leak...you'll hear it...
      Good luck,
              Bilbo