Return line to pump, valve? - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• Return line to pump, valve? by flapjack on 26 Feb, 2009 11:37
• Is there supposed to be a ball and spring type check valve where the fuel return line goes back to the pump from the injector?
  The red arrow in the picture below, is that where it is supposed to be?
  
• #1 by vanbcguy on 27 Feb, 2009 09:13
• Nope, what you see is what should be there (although that fuel line routing is a little strange)
• #2 by Hey on 27 Feb, 2009 10:23
• Tdi-e pump have a valve there.
  
  When idling, the valve is closed, and only a very small hole allows diesel to get out, the pressure is then higher at idle.
  
  Around 1800RPM-2000RPM the valve begins to open and more diesel can flow... at very high RPM a lot of diesel can flow helping keep the temperature down.
  
  I used this valve on my m-tdi pump.
• #3 by bert on 27 Feb, 2009 13:29
• you cant use red diesel with that clear pipe  :lol:
  Bert
• #4 by Rabbit on Roids on 27 Feb, 2009 13:34
• lol, i run red diesel with clear lines. not clear injector return lines tho.
• #5 by Turbinepowered on 27 Feb, 2009 13:46
• Totally unrelated question, but where did you get a brand new (or surely new looking!) accelerator cable?
• #6 by blkboostedtruck on 27 Feb, 2009 14:16
• the return bolt should have a special marking on it's head a # with a circle and a slash! or it will just say (OUT) it also has a filter inside the bolt thats how the pressure is maintained for internal pump pressure!
  Duane
• #7 by vanbcguy on 27 Feb, 2009 17:21
• Just for the record, my pump has an out bolt that does NOT say OUT on it anywhere.  I actually pulled it off the pump a couple weeks ago purely because I was sure it couldn't be an OUT bolt without saying OUT on it... But once I pulled it, it has the tiny OUT bolt sized orifices on it.
• #8 by flapjack on 27 Feb, 2009 18:23
• The reason I ask is the return line is leaking. So I replaced them, twice. Once with regular lines, then with these clear disco lines.
  Still leaking.  I thought there was something missing that was supposed to keep the pump from pushing fuel back thru the return line.
  
  Turbinepowered:
    The cable is new, I got it from my cousin in Croatia. I can ask him to send me more if you, or anyone else is interested.
  First I tried to order from a Canadian co. They sent me a self adjusting clutch cable instead.
• #9 by Rabbit on Roids on 28 Feb, 2009 10:06
• where is/are the lines leaking? from the injector? or closer to the pump. sometimes it appears the return lines are leaking when the injector line is slightly loose. ive had it happen to me, thought my injectors were out to make me crazy, but i tightened the line on that injector, and ive never had fuel run down the front of my block since.
• #10 by flapjack on 28 Feb, 2009 18:02
• it's always the capped barb that leaks.
  I've replaced the cap, I;ve reversed the order of the hoses, same problem.
  I didn;t check the bolt to see if it says OUT on it... .maybe mine says F.U. on it
• #11 by jtanguay on 28 Feb, 2009 18:57
• Quote from: "Turbinepowered"

  Totally unrelated question, but where did you get a brand new (or surely new looking!) accelerator cable?

  
  
  hate to say it... but here it is  :lol:
  
  

  Quote from: "flapjack"

  it's always the capped barb that leaks.
  I've replaced the cap, I;ve reversed the order of the hoses, same problem.
  I didn;t check the bolt to see if it says OUT on it... .maybe mine says F.U. on it

  
  
  if its the capped barb thats leaking, maybe you just need a new one? this place has it for about $1.95, but looks to me like some injector return line with a 'plug' inserted.  so you could probably buy some injector return hose and make your own.
• #12 by flapjack on 28 Feb, 2009 21:29
• thanks but my 1.6td is in a '94 mk3. That cable is for a mk2. The pedal end is different.
  the '93-'99 section of that website doesn't have an accelerator cable
  
  i did try a new cap and using a piece of hose with a plug in it as well.
• #13 by jtanguay on 28 Feb, 2009 22:01
• Quote from: "flapjack"

  thanks but my 1.6td is in a '94 mk3. That cable is for a mk2. The pedal end is different.
  the '93-'99 section of that website doesn't have an accelerator cable
  
  i did try a new cap and using a piece of hose with a plug in it as well.

  
  
  but its still leaking from there?
• #14 by flapjack on 04 Mar, 2009 03:52
• Yes, still leaking.
  I checked the bolt, seems to be ok. I'm guessing I'm barking up the wrong tree.