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  #1  
Old 06-08-1999, 07:06 PM
SYDDONNA
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I am trying to check out the wiring that is plugged to the injectors ---what reading should I be getting across the plug when I crank the engine

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syd 81.300SD
72.300SEL 4.5

  #2  
Old 06-08-1999, 08:37 PM
M.B.DOC
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There is a "voltage" frequency sent by the computer to the injectors. The injectors are triggered in pairs by 4 sets of points(mounted in the bottom of the distributor).
  #3  
Old 06-08-1999, 11:52 PM
SYDDONNA
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this engine runs--misfires and is rough--- like it is not running on all cylinders---plugs are black ---have replaced plugs --new air filter---checked points ---checked all plug leads nicks and the suchlike also for resistance--checking timing and compressions tomorrow ------trying to figure out if there are any problems with the wiring to the injectors---have dicovered tonight that when pulling plug off injectors corrosion is very visable---so will clean them as well---any advice would be apprecciated ---need this engine up and running to see if rest of car works it was delivered to me on a low loader

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syd 81.300SD
72.300SEL 4.5

  #4  
Old 06-09-1999, 12:20 PM
WDurrance
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Hi,
Pull the distributor and check for oil on the trigger-points in the distributor base. You can also trace the problem on a scope. The injectors are fired in the following pairs: #1&5, 2&7, 3&6, 4&8. Usually when you see a problem on any of these pairs of cylinders...it's trigger-points.
Regards,
Randy D.


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W.R.Durrance
ASE Master Tech
Mercedes Tech 19 Years
  #5  
Old 06-09-1999, 09:11 PM
M.B.DOC
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Now that you have described the running problem as running rich I'll bet that the cold start relay is stuck, un plug the cold start valve & see if the engine runs better. Also the vacuum hose for the M.A.P. sensor has been known to leak.
  #6  
Old 06-09-1999, 09:12 PM
SYDDONNA
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thank you for all answers I received on this topic syd

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syd 81.300SD
72.300SEL 4.5

  #7  
Old 06-09-1999, 09:28 PM
SYDDONNA
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whilst I'm running rich I was spitting and banging and could not rev it up--all injector boots disintergrated and all injector plugs were coroded--(think its been standing a long time)no5 was welded solid with corosion --I am waiting for new injector plugs to be delivered---tried to get workshop manual from 1-800-for-merc --no luck --got told the old cd story--QUESTION --so M.B.DOC help me out here---- where is the cold start valve and the M.A.P.sensor--I feel I will have to replace N05 injector --but as soon as plugs arrive I will try it before replacing it

------------------
syd 81.300SD
72.300SEL 4.5

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