Author Topic: white screws  (Read 3618 times)

Fintail

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white screws
« on: July 21, 2010, 12:02:03 »
Dear All greetings from England

Over the years I have had great pleasure in helping fellow enthusiasts with injection problems, a little stumped with the latest arrival on my drive CO at 12-14 at 1500rpm and I suspect pump internals mal adjusted. is there a ball park out from stop for the white screws. All linkage timing dwell valve in order

Your support apreciated

John

ja17

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  • USA, OH, Blacklick
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Re: white screws
« Reply #1 on: July 22, 2010, 11:30:17 »
Hello John,

Make sure you have the correct fuel pressure and volume and all other tuning is to specs. Make sure your linkages are correct.
Not sure where these screws were set up when new.  I suspect they were set up somewhere in the middle of their range so they could be adjusted in or out.  Once they are adjusted too far out, the hex head of the screws moves past the small leaf springs and the "click" feeling becomes vague or goes away.  At this point the screws are in danger of falling out. 

Take care,
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Fintail

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Re: white screws
« Reply #2 on: July 22, 2010, 13:27:11 »
Hi Joe Thank you for reply
This car seriously messed with even the lingage geometry altered by someone cutting and brazing the control arm across the top of the engine result is runs richer as throttle opened. I read somewher here that CO is 2.8 at 1500rpm but cannot find it to clarify my memory

Thank you

John

jeffc280sl

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Re: white screws
« Reply #3 on: July 22, 2010, 15:47:00 »
The BBB states CO should be 1.5 - 3.0 at 1500 rpms with a partial load.  Your CO is off the chart.  Are you sure the tester is accurate. The white and black fip screws have a range of about 60 clicks from the CW stop.  The mid point would be 30 CCW clicks from the stop.

Fintail

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Re: white screws
« Reply #4 on: July 23, 2010, 09:50:49 »
Thank you Joe and Jeff
The information is invaluable Thank you, its the first time I have encountered such a mauled car. It was purchased unseen at auction wow (not by me) The big danger with these cars running rich for prolonged period is bore wear among other things, I have had to sleeve two engines.When stripped third stage rebore would have left a ridge on a standard engine.Still ran no smoke but difficult hot start due to low compression. Have fun  John

jeffc280sl

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Re: white screws
« Reply #5 on: July 23, 2010, 21:13:10 »
Fintail,

If your going to adjust the rack, white or black screws I suggest you count the clicks to their CW stop and record the data.  Then reset the screws and start adjusting.  That way you can always get back to your starting point because it is easy to get confused with CW and CCW adjustments using a mirror.  At least I found it confusing.  An portable afr meter would also help greatly.  And then there's the MAP sensor and ...

Search under that topic and you will find my post of fip tuning.  Good luck