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Old 04-14-2003, 11:18 PM
LOWMILE's Avatar
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Join Date: Mar 2003
Location: Chicago Il.
Posts: 101
HElP! Newbie Vacuum question

New to Merceces, I have a hunting idle and stumble off idle where is best place to check what kind of vacuum I am getting? Some say close to the manifold, and yet other posts say take it at the map sensor? Where is the best place and what kinds of values am I looking for? 1972 350SL 23K miles. Also the large vacuum line that runs from the MAP sensor to the back of the engine...I have a broken back is it a big deal to replace it it looks like it might be a pain to pull it off the back of the engine I dont want to get it off and then not be able to get my fat fingers in behind the engine to replace it. I have so far put new copper plugs wires and cap and rotor changed fuel pump and filter. The car idles like silk at times and at times the idle "hunts" or "lopes" between 550 and 650 rpm. The best performance came after i got rid of the platinums, put in copper plugs cleaned the flame trap and replaced the fuel filter. Any help would be great. I have a timing light dwell analyzer and mity vac and large amount of metric handtools.
I love low mileage cars!
1972 350SL 23,000 miles
Now 1969 280SL
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