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  #1  
Old 02-08-2006, 06:21 AM
Gary Ganaway's Avatar
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380SE Cold Idle-new questions for advice

Still tracking down cold idle issue. Car starts fine and rpm goes to 1000/min but there is a miss or rough idle or stumbling. ( feels like its not getting enough fuel )This exists until temp reaches about 60-80C then it is fine and runs like a dream with idle at 500/min.

-plugs, dist. cap, rotor are recent and I checked them again and see no problem
-new water temp sensor
-new OVP
-cleaned idle control valve(not very dirty). Pull off connector and idle increases so appears to be working
-frequency valve buzzes
-cannot find any problems with vacuum lines

have not checked cold start valve but since car starts right up I would think its ok?

thought I may have got "bad" tank of gas so I was able to fill up yesterday but so far this has not seemed to make any difference.

Would oil temp sensor or fuel pressue regulator be a culprit?

Appreciate any advice of where to look next. Thanks

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Old 02-08-2006, 12:51 PM
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Just as it is impossible to say what it is (from a far), it is impossible to say what it isn't. But for practical purposes I would say it absolutely it isn't the cold start valve, the temp sender, or the fuel pressure regulator.

Some statistical analysis and theoretical concept would tell me that. A scope could confirm it but a statistical approach would send me looking at plug wire ends. Possibly a leaking or restricted injector/s.
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  #3  
Old 02-08-2006, 03:37 PM
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Yeah, I have new set of wires coming. I figure its due anyhow since I still have the originals. However, this morning, about 25F, it started right up with no stumbling and ran fine, which has me thinking it may have been a bad tankful of gas. Only other thing I notice, and its done this for some time, is an occasional blip or miss when stopped at idle, about every 15 -20 seconds or so...very slight and probably someone sitting in the passenger seat wouldn't even notice.
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Old 02-08-2006, 06:24 PM
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The little idle blips are almost unavoidable. When it happens on mine, I can see the oil pressure needle dip each time. It might have something to do with the way the computer responds to the O2 sensor. You can try tweaking the fuel/air mixture if you have a meter with a duty cycle reading.
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Old 02-13-2006, 03:37 PM
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Update----installed new plug wires and no more cold start issues. One of the wires had a lot of corrosion on tip where it goes into plug connector. These were the original wires.

Now I have a warm start issue and from searching it may be the fuel accumulator which I will check. Today I put in can of Techron and drove about 30 miles on a the Interstate and after car sat about 1 hour it started up much better. Previously if the car sat from say 1 hour to maybe 3-4 hours it was hard to start. Guess it could also be an injector problem but I will see haow the techron a treatment does the next couple of days.
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Old 02-26-2006, 03:10 PM
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thanks Steve Brotherton

Put in new fuel accumulator and hot/warm start problem is solved. (Hardest part of the job was trying to loosen stripped head screw for clamp around the old accumulator)

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