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Author Topic: Built a mech. VE-pump. Need help!  (Read 576 times)

February 03, 2018, 08:05:45 am


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Built a mech. VE-pump. Need help!
« on: February 03, 2018, 08:05:45 am »
I swapped my W124 Merc 2.5 IDI to 2.9 DI OM602.98 engine. So I needed mech. VE pump, I went for the easiest way for me and built one.

I used VW Golf pump body and a lathe to fit 20mm shaft and all other Merc's pump internals into Golf's pump. Everything is fine, car runs great, starts perfectly. You can almost say the build went fine, but my sar does not feel like 300nm beast like it should be in stock.

I turned the fuel increase fuel to the point where rpm's increasing on it's own, so it should be maxed out. I also did a governor mod and it got better. So I asked guys from STD forum whats wrong and they told me that the mech pump governor lever does not move the control collar enough and governor lever needs modification to give that extra stroke. And also mentioned guys from VW forum have done it but the DIY thread was gone.

So maybe there is someone who can help me, would be great.

Reply #1February 03, 2018, 10:49:14 am


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Re: Built a mech. VE-pump. Need help!
« Reply #1 on: February 03, 2018, 10:49:14 am »
Recap - your residual pressure/idle screw is all the way out so the accelerator lever is resting against the pump case, correct?  Turning the max fuel in further causes the rpms to hang or accelerate even with the accelerator lever at idle position, correct?

At that point, you can usually jump a spline between the accelerator lever and the accelerator shaft of the pump.  Jump a spline so the shaft moves toward idle and the lever moves toward more fuel.  You will then need to turn the max fuel screw in quite a bit but you will get higher max fuel. 

If you find that you have done that to the point that the max fuel screw is all the way in and bottoming on the case, you can drill the case a couple mm to give more adjustment.  If that still does not give enough fuel, then you will want to fit a different control lever assembly from a DI pump.  A couple choices would be the Land Rover 200/300 mechanical pumps or the Cummins 4BTA.  There are probably others.  You need the control lever to match the accelerator lever position in the pump case and to match the lever that comes down from the aneroid assembly. 
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