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-   -   mw pump plunger replacement (https://mercedesforum.com/forum/diesel-performance-49/mw-pump-plunger-replacement-52534/)

The Dude 11-27-2012 01:09 PM

mw pump plunger replacement
 
We all know that you can ship an M-pump core off to finland & it comes back with larger plungers/ delivery valves & is properly bench tuned/ calibrated for ~2 grand.
But what can we do for the mw pump? I have seen multiple threads where the discussion was started but never finished. Is there really a direct plunger/dv swap for the pump?
I realize 10mm is way too large, looking for close to 7 or 8mm.

I found this one:

& i dont believe this one is legit, y would someone throw in larger elements before installing a turbo?:


I ordered the last of my holset hx30 fittings for the oil supply, will post when i put it in, gona need more fuel- for the time being i might install a propane system or methanol injection cause i got all this methanol sitting around from my still.

The Dude 11-28-2012 11:05 PM

so theoretically could a lpg system regulated by boost pressure add decent horses? propane is probably more cost effective than diesel nowadays with petrol prices.
Im gonna install the hx30 now i have all my fittings- my orifice will be a 2mm hole in a flat head 8/32 screw tapped into one of the 1/8npt fittings. i have a 0-200psi gauge after the orifice atop the oil supply inlet.

the oil return is in exactly the same place as my garett, so i will use the stock down pipe.

I will be the first person to actually test the hx30 on an om617 block, will post results.

The Dude 11-29-2012 12:55 AM

also, ever since egr capoff & n/a manifold replacement- my car "flares" on shifts. That is it eases into the next gear unless i floor the pedal. the engine also occasionally refuses to shutoff when the key is turned untill i press the ebrake or open/ close the doors.
I would blame the vcv or the green valve on the tranny but when u factor in the shutoff problem I want to say we have a leak or a failing vacuum pump. I have put thousands of miles on the car with this problem, the transmission is not bad because the fluid is still red- no leaks.
How would i go about testing the vacuum pump?

The Dude 11-29-2012 01:50 PM

I saw your attachment not attachment(s); What i meant was that after hours of google searching i could not find any videos of an hx30 installed or running on an om617... google images came up with an hx35, youtube an hx35 in a g series that you commented on- "why is it so slow" :) your attachment fails to show the turbo, can you point me to the source of where you found the pic?

It cannot be the door locks; I have a w126 with an accessory pump in the trunk - all my doors go up and down with my remote because i removed the driver controller sw & ran a vac line & lock valve.

edit: found the orifice (green) same one since i got the car when it was shifting hard. replaced rubber tube on modulator->black hose, holds pressure on mvac now & flare is much less noticable

The Dude 11-29-2012 05:58 PM

This exactly describes my problem(from an article here:Mercedes-Benz Transmission, Steve Brotherton, ImportCar, February 2002)

"In practice, the shift point can be altered to achieve some measure of control during certain flaring conditions. The most common flare occurs in the 3-4 shift, with some occurrences in the 2-3 shift. The flaring condition exists due to a lack of shift overlap caused by slow filling of a clutch pack either through greater fluid volume needs of loose clutch packs or fluid losses through pack seal leaks (described above). Early cars also had the condition due to low shift pressures, adjusted to keep the 1-2 shift tolerable. Cars with this condition can have their relative shift pressure improved by getting the high shifts sooner so they will be made with greater throttle, giving lower vacuum and greater pressure. If the shifts are made as the throttle is backed off, then the pressure drop in the modulator is very high. "

But other than driving heavy on the gas & reducing pedal pressure when you sense the on-coming shift-- The article does not point out an adjustment solution, any suggestions?


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