Author Topic: Best way to readjust the fuel injection pump  (Read 4936 times)

Travis71280

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Best way to readjust the fuel injection pump
« on: May 01, 2011, 21:43:22 »
Hi all, I was wondering what is the best way to readjust the fuel injection pump as it pertains to idle mixture and the idle air screw? I finally got the warm running device back in the car, and after restarting the car the motor keeps laboring (stumbling and catching itself steadily). I plan on going through the linkage tour again, but I was just wondering what was the best starting point to start adjusting. Thanks again for all the help.

ctaylor738

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Re: Best way to readjust the fuel injection pump
« Reply #1 on: May 02, 2011, 17:27:27 »
i assume that you are getting an oscillating idle, which is generally caused by a lean condition. 

I would first check if the WRD is working.  Remove the little air filter, start the car cold, and see if you can feel suction when you stick your finger where the filter screws in.  This is the extra air supplied to raise the idle when the engine is cold and should decrease to nothing as the engine warms.  If no suction, you still have WRD problems.

If the idle problems continue after warmed up, you might try going a few cllicks to the right on the idle adjustment on the back of the pump to richen the idle mix.  This might help the cold and warm-up idle as well.
Chuck Taylor
1963 230SL #00133
1970 280SL #13027 (restored and sold)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

ja17

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Re: Best way to readjust the fuel injection pump
« Reply #2 on: May 03, 2011, 00:39:21 »
Hello,

Yes, check the linkage first, then do the "split linkage test" to determine if the engine is running rich or lean. Check back with us with the results.
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

Travis71280

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Re: Best way to readjust the fuel injection pump
« Reply #3 on: May 04, 2011, 16:38:39 »
Thanks everyone, I'm going to start tinkering with it today, but I did have a question pertaining to the warm running device, I rebuilt it the other day, but in the process the guide rod got accidentally tapped out (the wrd was froze up so i tried tapping it out). I soldered the guide rod back into the piece that sits on the spring. After reassembling it, I noticed the guide rod  sits even with the opening. Is thats how its suppose to sit at room temperature? If not, how far out should the rod stick out at rest?

ja17

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Re: Best way to readjust the fuel injection pump
« Reply #4 on: May 04, 2011, 19:42:49 »
Do you have a picture?  Not really sure what the situation is.
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

Travis71280

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Re: Best way to readjust the fuel injection pump
« Reply #5 on: May 05, 2011, 15:54:57 »
I'll try and get a picture of it later this week, but the rod the arrow is pointing to got accidentally tapped out of the plunger assembly. Just wondering how far out that rod is suppose to stick out from the warm running device once assembled, right now it doesn't stick out at all. ???

ja17

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Re: Best way to readjust the fuel injection pump
« Reply #6 on: May 05, 2011, 16:33:55 »
No need to send a pic. I see what the situation is. The length the pin extends depends on how far the "heat feeler" pushes it down. You may want to find a good used spring assembly. One of the IP rebuilders probably has a drawer full of good used ones.

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

Travis71280

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Re: Best way to readjust the fuel injection pump
« Reply #7 on: May 05, 2011, 19:12:57 »
Thanks, I guess thats my problem, I ran the car again and I'm fighting an over rich issue (checked the new spark plugs, they were all black and sooty). I'm guess thats coming from me putting the guide rod on too short after I tried reattaching it?

ja17

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Re: Best way to readjust the fuel injection pump
« Reply #8 on: May 06, 2011, 02:45:35 »
Hello Travis,

So did you get the IP freed up?  How did it work out?
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

Travis71280

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Re: Best way to readjust the fuel injection pump
« Reply #9 on: May 08, 2011, 19:00:12 »
It's working at least, I noticed the rods moving and the air is cutting off on the WRD, its just I attached the rod on too short (car runs way too rich because of that, just like putting a lot of shims under the warm running device). Still don't know how long the plunger is suppose to be.