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Engine Specific Info and Questions => IDI Engine => Topic started by: sgnimj96 on January 15, 2014, 12:57:45 pm

Title: resealed pump not pulling fuel properly
Post by: sgnimj96 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?

Title: Re: resealed pump not pulling fuel properly
Post by: 745 turbogreasel on January 15, 2014, 01:38:33 pm

its a reverse rotation  pump?

Title: Re: resealed pump not pulling fuel properly
Post by: sgnimj96 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

Title: Re: resealed pump not pulling fuel properly
Post by: libbydiesel 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.

Title: Re: resealed pump not pulling fuel properly
Post by: sgnimj96 on January 15, 2014, 04:40:36 pm

      :)  I'll check that.      Thankyou!

Title: Re: resealed pump not pulling fuel properly
Post by: sgnimj96 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! 

Title: Re: resealed pump not pulling fuel properly
Post by: fatmobile 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.

Title: Re: resealed pump not pulling fuel properly
Post by: libbydiesel 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. 

Title: Re: resealed pump not pulling fuel properly
Post by: 745 turbogreasel 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.

Title: Re: resealed pump not pulling fuel properly
Post by: libbydiesel 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.