Air in diesel pump? - General - VWDiesel.net The IDI, TDI, and mTDI source.

• Air in diesel pump? by roundel on 17 Dec, 2006 19:03
• Hey guys I recently tried to run diesel purge through my car and it didn't work too well. It had no suction to take in diesel purge. So I gave up on the diesel purge but now my car is having trouble starting. After sitting all night I doesn't like to start in the morning. I have to lay the gas pedal to the floor and try to turn it over for like 30 sec before it will start. For the rest of the day it will start perfectly fine it is only after sitting all night or for long periods of time.
  
  I am thinking that when I did the diesel purge that I let a lot of air into my fuel system and that the engine is starved for fuel after sitting all night. ( I am a complete diesel noob so I am probably wrong)
  
  Does anyone have any ideas why it might be doing this and how I can fix it. It ran and started fine before the diesel purge I only did it to clean up the injectors a little.
  
  Any help would be really appreciated. Thanks a lot
  
  Also it seems to idle higher in the rpm's now and it is a lot louder.  Don't know if that makes a difference. Thanks
• #1 by jtanguay on 17 Dec, 2006 20:30
• usually any air will be sucked through the pump and it will run like crap for the first 20-30 seconds until its all out.  sounds to me like you left a hose on loose or something...?
• #2 by roundel on 17 Dec, 2006 20:39
• I didn't think so but I will definetly check it when I get back to my car. Thanks
• #3 by roundel on 17 Dec, 2006 22:47
• Check the lines before leaving school and they were both tight no leaks. Anything else you can think of? Thanks
• #4 by burn_your_money on 17 Dec, 2006 23:10
• Are there any air bubbles in the lines when the car is running?
  
  I'm thinking air is seaping in overnight somewhere which is why it sucks to start in the morning but then the rest of the day is it fine because there is still lots of fuel in the pump. You could install a lifter pump temporarily until you get this sorted out, that should greatly inprove your startups, actually it is a good idea to have anyways
• #5 by roundel on 18 Dec, 2006 07:59
• Hey I just checked after starting it hard this morning and there is no air bubbles in the lines when the car is running. Thanks for the opinion though.
  
  On another note I have an exhaust manifold leak which I discovered this morning.  
  
  I appreciate the help guys. Thanks
• #6 by jtanguay on 18 Dec, 2006 10:03
• have someone else crank it over in the morning and have a flashlight handy to better see if there is any bubbles going to the pump.
• #7 by roundel on 18 Dec, 2006 17:54
• I did that this morning didn't seem to be any bubbles in the lines go to the pump. Only a very few right at start up like maybe 10 bubbles and than no more. Thanks guys
• #8 by LeeG on 18 Dec, 2006 21:53
• sounds like a bad glow plug could be a possibility
• #9 by burn_your_money on 19 Dec, 2006 04:14
• or a bad injector, maybe when you did the purge you cleared some gunk out of the pump but since you weren't able to do the whole thing it didn't clear the injector. Try running some conditioner through your engine.
  Maybe it's an unlreated issue to the purge. It might just be a coincidence that it happened at the same time. Drain the water from your seperator and see if that helps any
• #10 by roundel on 19 Dec, 2006 18:50
• Quote from: burn_your_money

  Drain the water from your seperator and see if that helps any

  
  
  Would someone mind telling me how to go about doing this. I really have no idea. Thanks a lot guys
• #11 by Darkness_is_spreading on 19 Dec, 2006 21:19
• You have two water seperators, one on the fuel filter by the motor, and one near the tank.   The one at the fule filter is alot easier to open than the one near the tank......
  
  
  Open the little white valve on the bottom of the filter, and fuel+ water will drain out,  do this for 6-8 sec.  Then open your filter and fill it with fuel ( If it has the Fuel Pre Heater).   Then go to the fuel filler, and look under for a little black box......  (  open the valve which might me stiff and crank off, do this for 6-10 sec)......  Catch the diesel if you can
  
  
  At this point you may have alot of air in the lines..... So I suggest opening up your IP lines and cranking the motor until you have steady fuel flow from the IP.    Crank the lines closed while cranking   but make sure the GP (glow plugs) are off.      
  
  Another alter to this step is to crank the motor with the lines open, and then stop cranking and  close the IP line, then crank again and close the next line.
  
  You may get alot of diesel all over the place,  so run a rag near the open lines to catch as much as possible.  This will throw off a fuel leak if there ever is one in the future.
• #12 by fatmobile on 20 Dec, 2006 21:47
• There is a screen in the "OUT" bolt that might be clogged.
   Put a normal banjo bolt in place of the restrictive "OUT" bolt while running your purge.
   You should have a filter somewhere in the loop when using the diesel purge.... even if it's a plastic inline filter.
   with the normal banjo installed on the output, flow through the pump will be greatly increased.