[W126 Coupe] Slightly High Idle - Possible Causes

[JohnJayKimrey1 at aol.com]

Dear  Larry, Neil, Tim and Anyone Else:
I have checked for vacuum leaks and found none so far using my mytvac and  
vac. gauge. The vac. gauge at idle reads 21 inches+ - 1/4 to 1/2 bar(slow)  
fluctuation.Is this acceptable or point to a slight leak and would this give me  a 
300 rpm idle problem( 850 at idle)? I removed and cleaned the fuel  
distributor,plunger and air valve mechanism. There was some varnish but the  plunger 
was working fine. I also replaced the injector seals as the  fuel lines were off 
and these I thought were a possible area for vac.  leaks. I also removed the 
cold start valve reattached the fuel  line and with ign. on tested for a 
possible fuel leak-checked good. I  sprayed water over the engine at idle to try 
and detect a leak and found no  change in vac. reading. I am beginning to think 
my problem may lie elsewhere  such as  the idle control unit(ICU). Everyone 
has advised that there  is no sure way to test without special equip. so I guess 
my next step is to  bite the bullet and buy one unless someone can point to 
something else I can  try.
By the way , I really to appreciate all the advice I have received.
Thanks!!



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