Author Topic: resealed pump not pulling fuel properly  (Read 2633 times)

January 15, 2014, 12:57:45 pm

sgnimj96

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resealed pump not pulling fuel properly
« on: January 15, 2014, 12:57:45 pm »
  I wanted to test the pump before installing it so I put the pump in a vice,  mityvac'd to fill it with fuel,  then put a socket on a drill (variable speed) to spin it over.  Jar of diesel with hoses going to the in  and out ports. 
 
  Its not pulling fuel,  just makes a lot of air bubbles.   In fact it seems to pull fuel normally when i rotate the drive shaft counter-clockwise (backwards),   until the nut spins off.     

  This is very strange,   I even re-opened the pump to check the vanes.  Everything seemed in order, put it back together,  same thing.    I don't know what I did wrong,  but something is.    Put 12volts on the solenoid,  no difference.       How is it possible to only  ??? pull fuel by turning the pump backwards?
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #1January 15, 2014, 01:38:33 pm

745 turbogreasel

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Re: resealed pump not pulling fuel properly
« Reply #1 on: January 15, 2014, 01:38:33 pm »
its a reverse rotation  pump?

Reply #2January 15, 2014, 01:48:34 pm

sgnimj96

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Re: resealed pump not pulling fuel properly
« Reply #2 on: January 15, 2014, 01:48:34 pm »
It wasn't before I took it apart (lol) .   from a 1.6 CR engine...  
 Double checked the banjos,  out has the filter in it.        It easily primes with the mityvac.
I know the vanes aren't stuck,  threads about that are the closest i can find similar.     
      I must be way off
« Last Edit: January 15, 2014, 02:06:20 pm by sgnimj96 »
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #3January 15, 2014, 04:24:44 pm

libbydiesel

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Re: resealed pump not pulling fuel properly
« Reply #3 on: January 15, 2014, 04:24:44 pm »
If you put the outer ring of the vane pump in upside down it reverses the flow direction.

Reply #4January 15, 2014, 04:40:36 pm

sgnimj96

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Re: resealed pump not pulling fuel properly
« Reply #4 on: January 15, 2014, 04:40:36 pm »
      :)  I'll check that.      Thankyou!
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #5January 15, 2014, 08:05:51 pm

sgnimj96

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Re: resealed pump not pulling fuel properly
« Reply #5 on: January 15, 2014, 08:05:51 pm »
      That was it!        I flipped it over cleaning it,  thought it wouldn't go in up side down being tapered...   yikes! 
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #6January 16, 2014, 07:26:13 pm

fatmobile

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Re: resealed pump not pulling fuel properly
« Reply #6 on: January 16, 2014, 07:26:13 pm »
 Soo if we find a nice pump that was built to spin the other way;
 we can fix that.
Tornado red, '91 Golf 4 door, with M-TDI 12mm pump, south bend clutch, VNT-15 turbo, 02A trany
MK4s: 2000 TDI jetta, 2003 TDI wagon, 2000 golf 2.0 gasser.
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Reply #7January 16, 2014, 07:37:43 pm

libbydiesel

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Re: resealed pump not pulling fuel properly
« Reply #7 on: January 16, 2014, 07:37:43 pm »
Reversing the vane pump isn't the only issue.  The plunger is different also as is the drilling in the pump case to the dynamic advance piston. 

Reply #8January 16, 2014, 07:38:19 pm

745 turbogreasel

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Re: resealed pump not pulling fuel properly
« Reply #8 on: January 16, 2014, 07:38:19 pm »
I think the  channels in the head are different too.   Dieselmeken has mentioned EDMing them to go the other way, and I doubt he'd bother if  you  can just flip the ring.

Reply #9January 17, 2014, 06:07:00 pm

libbydiesel

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Re: resealed pump not pulling fuel properly
« Reply #9 on: January 17, 2014, 06:07:00 pm »
My understanding is that the channels in the distributor head are the same.  The channels are cut on the plunger different, tho, to prevent an engine from being able to run backwards.  By rotating the plunger in the correct direction, the 'fill port' closes before the 'delivery port' opens.  Regardless, the plunger and head are a matched set so it is fairly irrelevant which one is different.