Author Topic: 280 SL 69' idle screw out of the spring leafs (Injection Pump)  (Read 6269 times)

fabricio

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I HAD THE ENGINE OFF AND TURNED THE THUMB SCREW LIKE 3 TO 6 CLICKS COUNTER CLOCKWISE  BECAUSE I WANTED LEANER AND IT FELT NORMAL , I PUSHED IN AND GOT THE SLOT FINE BUT THEN  THE THUM SCREW GOT STUCK , IT DID NOT MOVE BACK, IT STILL TURNS BOTH WAYS BUT LIKE 8 TURNS EACH WAY.
SOME BODY CAN TELL ME WHAT TO DO
SHOULD I TAKE THE COVER OFF?
I HAVE ALREADY PUT W40 AND DONT COME BACK
HAVE NOT STARTED THE ENGINE  IN CASE IT WILL DAMAGE SOMETHING

THANKS
« Last Edit: July 25, 2011, 04:15:16 by fabricio »

jeffc280sl

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Re: FUEL ONJECTION PUMP THUMB SCREW STUCK
« Reply #1 on: July 23, 2011, 16:03:00 »
The thumb screw is spring loaded so it should move outward on its own without any pressure to engage the idle screw.  I would simply grab it with my fingers and pull it back. 

fabricio

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Re: FUEL ONJECTION PUMP THUMB SCREW STUCK
« Reply #2 on: July 23, 2011, 19:47:19 »
THANKS, SO THE PROBLEM IS THAT DOES NOT GO IN. SHOULD  I TAKE THE COVER OUT?

ja17

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Re: Fuel Injection Pump Thumb Screw Stuck
« Reply #3 on: July 24, 2011, 00:15:10 »
Hello,

If the thumbscrew is adjusted all the way back it will press against the spring loaded screw and will not dis-engage.  Try screwing the thumbscrew back in and see if it releases.
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

fabricio

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thumb screw on back of injection pump 280 sl
« Reply #4 on: July 24, 2011, 00:16:01 »
in my car this screw spins when the engine is runig, is that normal or i have a problem there.

Cees Klumper

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Re: Fuel Injection Pump Thumb Screw Stuck
« Reply #5 on: July 24, 2011, 05:32:57 »
It should not be turning when the engine is running - like you have reported, it appears to be stuck engaged. Have you tried Joe's suggestion of turning it clockwise a couple of turns, then pulling it outwards to see if it will disengage again? If not, if it were my pump I would be tempted to try and remove the cover to see what is keeping it from disengaging.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

fabricio

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Re: Fuel Injection Pump Thumb Screw Stuck
« Reply #6 on: July 24, 2011, 12:12:42 »
THANKS GUYS BUT ANYONE CAN TELL ME THAT IF I HAVE TO TAKE OFF THE COVER COULD BE ANY POSSIBILITY TO DAMAGE THE PUMP?

« Last Edit: July 24, 2011, 17:46:26 by fabricio »

fabricio

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Re: Fuel Injection Pump Thumb Screw Stuck
« Reply #7 on: July 24, 2011, 17:49:19 »
I took the back cover off and the thumb screw blade, spring and hex nut in the pump are fine.
the problem seems to be that the hex nut is out more than usual and that is why the thumb nut was spinning with the engine running, at last it came out more and that is why  i could not move it but the hex nut in the pump turns fine.

what is happening, is there something bad en the pump or there is away to put it in again?
« Last Edit: July 25, 2011, 04:13:58 by fabricio »

fabricio

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280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #8 on: July 24, 2011, 23:54:03 »
i noticed that the thumb screw was spinning when engine running so i turned it counter clock wise and i felt the notches were gone. took out the back cover and the pictures show the head of the hex nut is out of the spring leafs.
PLEASE, anyone tell me how to fix it ?

« Last Edit: July 25, 2011, 04:00:45 by fabricio »

jeffc280sl

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Re: 280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #9 on: July 25, 2011, 19:14:31 »
You need to re-engage the idle screw adjuster.  Take a flat screw driver and turn the screw CW until the head reaches the leaf springs.  Gently move the leaf springs out of the way and continue to turn the idle screw CW.  Once you are flush with the leaf springs you will be able to feel clicks again.  I suggest you take the idle adjuster to the CW stop.  If my memory is correct I think the effective range of this screw is 64 clicks.  Once you have reached to CW stop I suggest you rotate the screw 32 clicks CCW to the mid point of the range.  Try and start your idle adjustments from there.

fabricio

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Re: 280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #10 on: July 25, 2011, 20:16:48 »
Thanks a lot , the problem is the dificulty to reach there and i supose i have to use two tiny screw drivers to separate the leafs
I will let you know

jeffc280sl

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Re: 280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #11 on: July 26, 2011, 01:33:38 »
I know it's difficult to work in this area.  I have tuned the much smaller white and black adjustment screws many many times.  It can be done with patience.  Good luck!

fabricio

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Re: 280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #12 on: July 26, 2011, 08:26:23 »
i made it! with two screw drivers! was easy

thanks again! :)

jeffc280sl

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Re: 280 SL 69' idle screw out of the spring leafs (Injection Pump)
« Reply #13 on: July 26, 2011, 14:18:17 »
Good news,  glad it worked out.