250/265 fuel pump upgrade

Discussion in 'Megane Projects' started by ianplymouth, Nov 9, 2020.

  1. Hi all
    As a couple of trackdays have been cancelled and i haven't got one till December, i thought this was a good time to sort out my fuel system.

    When i was at EFI getting it mapped it was the fuel pump that was holding things back.

    I haven't shown how to get the pump out, i'm sure if you can't do this you shouldn't attempt the pump change.

    As the mk2 pump takes the Deatchwerks DW65c, i was told that the mk3 one was different and not strippable to replace the pump.

    This is the unit
    50583983463_171594eee3_k.jpg PXL_20201105_152625886 by Ian Austin, on Flickr
  2. Next was to split it down to get at the pump

    If you push down on the top, it then shows a circlip only on the one that has the spring on.

    50584845742_81436899c0_k.jpg PXL_20201105_152659399 by Ian Austin, on Flickr
  3. once that has been removed the top can be lifted up, but be careful the pipes are quite stiff and will need easing out, then you can unclip the wires to give you a bit more room.

    There are also some clips down near the pump but that's later

    50583984553_eaf41ffc0b_k.jpg PXL_20201105_152849315 by Ian Austin, on Flickr
  4. Took a while to figure out how the pump is held in the housing and figuring the best way to get it out.

    This is how i got around it, might not be the best but it worked.

    There are 3 points where the two parts are fixed together, it looks like they fitted plugs and heated them to stick the parts together.

    I used an 8mm drill bit and drilled in about 10mm, if you drill it slowly you will hear the tone of the cutting change, thats when you need to stop.

    Drill out all three.

    50584846342_c9bc612555_k.jpg PXL_20201105_155705712 by Ian Austin, on Flickr
  5. then the inner part will come out, you may need to gently ease it from side to side as i think when they melted the plugs they got in the gaps.

    this is it stripped out of the housing

    50584846962_ac51a2975c_k.jpg PXL_20201105_155755554 by Ian Austin, on Flickr
  6. you now unclip the wires to the pump.

    getting the filter off of the bottom is the next thing, there are three points where the filter is held, they need to be prized up gently so as not to break the cage.

    50583993793_4e3fee4b29_k.jpg PXL_20201109_130703286 by Ian Austin, on Flickr

    50584115263_1580887096_k.jpg PXL_20201109_130703286 by Ian Austin, on Flickr
  7. once the filter is off, the pump can be pulled out, mine was a bit stuck maybe due to it being in there since it was assembled in the factory, a gentle prise between the pump and the housing will free it.

    I cut the wires to the pump and removed it

    250-265 pump on the left, my old 225 pump on the right, not much difference, so i bit the bullet and ordered a DW65w, was thinking about the DW300, its a direct replacement for the 65c, but with higher flow.

    Looking at the figures of both, the DW65c is way more than is required, i only need about 212ltrs a minute at 60psi and this pump is rated at 240ltrs a minute at the same pressure.

    50584848742_d755b02eea_k.jpg PXL_20201105_162721795 by Ian Austin, on Flickr
  8. i ordered this one, there seems to be a few variations, but it think its all to do with the bits that are added.

    50583997398_536ef6b859_k.jpg PXL_20201109_140420966 by Ian Austin, on Flickr
  9. this is what came in my kit

    50583991043_838ad80954_k.jpg PXL_20201109_104624013 by Ian Austin, on Flickr
  10. the whole pump is longer and as so the bottom sticks out too far.

    I trimmed about 10mm off of the outlet pipe, this then makes the top of the pump fit tight up to the housing, this then allows the fuel filter to fit on the bottom (more about that later) there is one "O" ring inside where the pump pipe goes, i added one of the ones that came with the kit, just to make sure it seals properly.

    as the pump wires were cut off and the new pump has spade terminals, the new pump isn't marked with + and -, i had to wire the pump to a battery to make sure it was going to pump when the ignition is turned on.

    Looking at the pump when fitted the positive is on the left or opposite to the standard fitted pump.

    50584853442_ece20d19ea_k.jpg PXL_20201109_120111713 by Ian Austin, on Flickr
  11. Using the the fuel filter that is fitted to the original pump.

    50584732581_10e503e661_k.jpg PXL_20201109_125242383 by Ian Austin, on Flickr

    I used a hole cutter to remove the middle of the plastic.
    this now, just about has enough room to fit on the base of the pump to hold it all together.

    50584854602_e43bae485f_k.jpg PXL_20201109_125858177 by Ian Austin, on Flickr
  12. When you first start to pull the pump out, there is this black fitting on the side, you need to fit this in the base, as it clips in it stays there, trying to fit it with this on its pipe then fit it back in it has to be spot on, its so much easier if you fitt it in the bottom first.

    50584735836_32395f6250_k.jpg PXL_20201109_131948476 by Ian Austin, on Flickr
  13. fit the pump unit back in, to secure it i used 3 40mm x m6 screws and nylock nuts, with washers under the head of the screws and nuts.

    The nuts need to go on the inside as you cant tighten them due to the lack of room.

    Its then putting the top back on, carefully feed the pipes back into the housing, at the same time feed the guides back into there holes, don't forget to fit the spring.

    Make sure it slides up and down okay, if so then fit the small circlip then its ready to refit into the tank.

    50584858377_56ca9c2261_k.jpg PXL_20201109_135317460 by Ian Austin, on Flickr
  14. v good write up and extremely handy, couple questions though...

    what sort power you running as factory pump are good to near 400bhp
    you've kept the two factory fuel pressure regulators (one on fuel rail) wont that mean the same fuel flow as factory pump
  15. Interesting to see this, I asked a 'specialist' to do this for me. After 100 kilometers my car stalled as they decided to not place a fuelfilter, as the DW65c would not fit the MK3 pump housing with it...
    Good luck :-) !
  16. Cheers Bobsan
    The injectors were maxed out at 399.8hp, as the 630 injectors are good for 450 it was deemed that the pump was also maxed out.
    I have left the regulators as stock, the one in the tank is 5.5bar by the way, i thought it was supposed to be 5bar.

    The new pump will supply more fuel and hold the pressure longer so that should then enable the injectors to be maxed out.
  17. Did the pump jam up with debris from the tank ???

    The fuel comes in through the little poppet valve in the bottom, i was thinking of not fitting the filter, but as i could shorten the pump and move it higher off of the bottom i thought it was worth the try, it is tight but its in there, will have to see what its like when its out on track.
  18. Ah ok so you're running forged engine... so then will need injectors and pump...nice
  19. Yes its a forged engine, i did do a build thread :blush:

    Its already mapped with 630 injectors, so the fuel pump was the last limiting part, well apart from the driver :grimacing:
    ROSS BATTEN likes this.
  20. Yeah, some debris got caught in one of the turbine blades in the pump. When I swapped back the OEM pomp and had a look at the DW, the turbine was clearly bend. Not running a fuel filter is not an option I'm afraid..
  21. That is why i was determined to fit one, glad i did now, so now you know how to do it :laughing::laughing::laughing:
    TsArno likes this.
  22. Good write up. I bet you had to take a brave pill cutting the new pump inlet down :grinning:
  23. It took the best part of the day it work it all out, measuring and measuring again cutting once all looked good to go, if it didn't go right it was going to be £150 down the pan.
  24. Forgot to mention in the how to posts, that there is a non return valve in the end of the pump, you can hook this out with a small screw driver, the standard pump doesn't have one so sure this is going to be fine without, the same pump i fitted into the Mk2 tank didn't have one either, must be something they have added.
  25. An update for you on this modification.

    I have now done 3 track days and around 1500 road miles and all is working great, not had the time to get it mapped yet but that will more than likely be March time.

    Merry Christmas to you all
    Conoboy, R.S.Sheldon, Brigsy and 2 others like this.
  26. Is the DW65c much noisier than the factory one?
  27. Yes it is noisier, but not obtrusive.
    I have taken the rear seats out so will sound louder, i don't remember my 225 being as noisy as this is
  28. autronix

    autronix RSM Club Member

    many thanks Ian for all the info. is this the non return valve?

    (also in the photo the polarity is shown)

  29. Yes it is a non return valve, i took mine out as i had to cut the tip down, i never had a problem in over a year with it not being there.

    Yes that is the continuity for the pump.
    autronix likes this.

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