Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Results 1 to 19 of 19

    Thread: injector pump losing prime?

    1. 08-25-2005 09:28 AM #1
      I have a 91 jetta gl non turbo and i purchased the car a month ago. I have had 11 vw diesels. In the last month I have driven the car about 4500 miles to Canada and back. Yesterday when i attempted to start it it took literally 2 minutes for the pump to draw the fuel up and then the car started and putted and then ran and I drove it to work. After 11 hours of work it did the same thing. This injector pump is slightly different than ones on my previous cars. It has a "pod" on top with vacumn lines going to it and then run to the passenger fender well where there is some sort of valve with one vacumn line and one wire. what is that stuff? Please advise am i looking at a pump rebuild or is there something else possible?

    2. Member KubotaPowered's Avatar
      Join Date
      Jan 27th, 2005
      Location
      Tucson, AZ
      Posts
      11,759
      Vehicles
      2013 PG GLI
      08-25-2005 12:54 PM #2
      Sounds like you have a slight leak somewhere thats allowing air to get in when its shut down.
      Quote Originally Posted by ..Derek.. View Post
      Clearly you aren't familiar with the "Golden Corrado". It's so clinically clean that in the event that you must urinate it must be done at least one zip code away in fear that it may catch a staph infection.

    3. Member
      Join Date
      May 17th, 2003
      Location
      Lancaster, PA
      Posts
      730
      08-25-2005 01:12 PM #3
      The 'pod' on top of the pump is a fuel enrichment diaphragm. It limits fuel when you are pulling out to prevent smoke and then uses a vacuum signal to give you more fuel once you are at higher RPM's.

      It does sound like you are getting air in your system. Have you done any work to the car lately, fuel filter perhaps. Sometimes a new filter won't always seal up properly. Also look for a puddle under the front of the engine. When the pump drive seal goes bad it can drain the fuel down out of the pump. Check all your fuel line connections and make sure they are tight. Perhaps changing the washers on the banjo bolts would be a good idea. Do you have any fuel around the throttle shaft of the pump? That is another common place I see air getting in. If there is nothing obvious sometimes putting a check valve in the line between the filter and the pump prevents the fuel from being able to drain back into the tank. It is ideal to fix the problem right if possible though, rather than just using a valve as a band-aid.


    4. 08-25-2005 10:26 PM #4
      Joel thanx for the info. I bought this car about 6 weeks ago and have not made any adjustments or repairs to the fuel system I have driven the car about 4500 miles and now the car will leak down in about 10 hours. What else can you tell me about the fuel inrichment pod and what publications could i read concerning it. I don't see any leaking fuel and I haven't touched the fuel system at all actually all of the banjo connections are tight because i tried shaking them all. Any other suggestions? Where can i get the proper timing setting for this year and this pump if I have to change pumps. Rast

    5. Member fukengruven1982's Avatar
      Join Date
      Jan 8th, 2005
      Location
      Hammertown
      Posts
      2,151
      Vehicles
      Fleet O' Diesel Dubs.
      08-30-2005 10:55 PM #5
      theres a check valve somewhere on you line between the tank and the injection pump...only allows flow one way....could be bad like my old 1.6....its a really cheap fix..cant hurt to try it...fuel is probably draining back to the water seperator /tank just a thought..

    6. 05-04-2012 02:19 PM #6
      Old post but maybe someone will reply.

      Anyone know the exact location of the check-valve to which fukengruven1982 refers? I don't recall ever seeing a checkvalve in the system. Mine is a '91 also, if that matters.

      If a check-valve exists, I probably have a piece of coagualted bio-fuel in it, keeping it from seating. I got some bad bio last year and plugged up my fuel pick-up screen ans well as the fuel filter. My curreent problems are probably an aftermath of that.

    7. 05-08-2012 11:56 AM #7
      I have had the loss of prime issue in a 1.6 VW diesel and it was a failed injection pump main seal. They rot after many years. You might want to check this. The timing belt and injection pump sprocket must be removed to replace the seal. I was swapping engines and had the pump removed when I replaced its seal. You may be able to replace the seal with the pump isnalled on the engine.

      --Nate

    8. 05-11-2012 01:14 PM #8
      thanx but pump was re-sealed about 10,000 miles ago and there is no exteranl sign of leakage anywhere. I did have an injector return line seeping but I replaced it. Fuel filter is new and I can suck fuel through it easily so that isn't source of starvation. Besides, it only happens when it sets overnight. Incidentally, this is an itermittant problem. That is the most odd and frustrating thing.....

    9. Member
      Join Date
      Apr 22nd, 2002
      Location
      NJ 08002
      Posts
      4,499
      Vehicles
      1 clunker & 2 nicer clunkers
      05-11-2012 09:39 PM #9
      Since its only an overnight thing, are you sure it's not glow plug related? Are you physically repriming the car to get it to start?

      -Todd

    10. Member
      Join Date
      Sep 12th, 2005
      Location
      Milwaukee, WI
      Posts
      1,913
      Vehicles
      1986 IDI Golf, 331K Miles.
      05-11-2012 10:24 PM #10
      One of my old Parts Place Inc catalogs had a short writeup about losing inj pump prime due to a failed rotary shaft seal as was mentioned. That can happen due to the cam belt run too tight for too long that wears the shaft bearing egg shaped that causes the seal to fail. The only permanent fix is a new pump housing or a new pump as there is no bearing insert; the housing material is the bearing. A possible workaround is a very low pressure electric inline pump that will prime the inj pump. if I did this, I would use the electric pump momentarily, long enough to get the engine started.

      I have been running my cam belt for many years and miles with a very slight lack of tension and the pump is still ok; no leaks. I have used a quart of biodiesel with every tank fill since the change to ULSD several years ago. Possibly these are good things to do as my inj pump is original and has never been resealed.

    11. Member
      Join Date
      Apr 22nd, 2002
      Location
      NJ 08002
      Posts
      4,499
      Vehicles
      1 clunker & 2 nicer clunkers
      05-12-2012 12:01 AM #11
      That doesn't make sence ... the mainshaft bushing is still available. Unless the wear is so great that it actually wears into the AL housing, I can't see it being an issue.

      -Todd

    12. Member
      Join Date
      Sep 12th, 2005
      Location
      Milwaukee, WI
      Posts
      1,913
      Vehicles
      1986 IDI Golf, 331K Miles.
      05-12-2012 10:01 PM #12
      Ok, a question has been revealed here. Does a VW inj pump have a rotary shaft replaceable bushing or not? Is there a difference between IDI and TDI versions? Expert assistance is needed.

    13. Member
      Join Date
      Apr 22nd, 2002
      Location
      NJ 08002
      Posts
      4,499
      Vehicles
      1 clunker & 2 nicer clunkers
      05-12-2012 10:03 PM #13
      Yes and yes.

      -Todd

    14. 11-19-2013 07:31 PM #14
      This is an old thread but I will jump in on it to see if it wakes up.

      My 91, non-turbo injector pump quit drawing fuel and would not build up enough primary pressure for the engine to run except at a "choked down" sub-idle. Thinking it was something to do with the supply pump I sent the whole pump to a guy for a poor man's "rebuild". He replaced all the internals of the pump, including the supply stage. He did not test and recalibrate, however. It came back with the same problem. Logic says that it must be a bad/stuck pressure control valve but that looks as if it has been replaced also.

      Anybody got any ideas? What, other than the pressure control valve, could cause the supply stage to essentially "bypass" so it will neither suck fuel nor build pressure in the main chamber? As mentioned above, I bet this relates to some jelled bio I got years ago but what could that "snot" have plugged up that wouldn't be cured by the items undertaken so far?

    15. Member
      Join Date
      Jun 18th, 2010
      Location
      sacramento,ca
      Posts
      801
      Vehicles
      1982 vw truck diesel, 79 rabbit 2 door diesel
      11-19-2013 09:14 PM #15
      As soon as I have problems like this I run clear lines with a filter at the inlet into a bucket of fuel. Make sure the fuel filter is clear, you should be able to easily blow through it.

      Make sure your out bolts pinhole is clear and you can blow through it.

      Try your best to make sure the pump has fuel if you have to gravity feed. I keep an electrical pump around just in case, or you can vacuum on the out side as well to get it through the pump.

      Then with a healthy starter/battery crank the car over for 10 seconds and see what is actually happening as far as fuel flowing.

      I like to rig up the inlet with clear hose and a big funnel that I tie to a hood hole.

      These pumps move fuel even just cranking so you should see your inlet supply move down steady.


      I have had more than one old pump that I tested on my daily drivers that had varying degrees of moving fuel. Some didn't seem like they were moving it at all and even sucking from the out side due to restriction problems.

      On these pumps I was still able to get the cars to start. I later would break these pumps down and completely clean and reseal. I would always see gunk in the vane area with sticky vanes to a degree.

      I have dealt with about a dozen pumps so far off of old engines and all but one came to life after doing this.

      I am not smart enough to know how the gunk impacts real world performance on pumps that don't seem at first glance to be tampered with or have broken parts inside. But like I have said, I have saved more than one pump that had goofy real world performance problems.



      I would now say all bets are off with a pump that was messed with and can't even draw fuel, especially hearing about no calibration. Just replacing parts, etc. isn't a good route to take. I would rather buy a dirty leaking pump that was working from a person on ebay, then reseal myself.

      Did you bypass the chasis I hope before sending that pump off? Something as simple as a plugged filter can stop a car dead in its tracks.

    16. 11-20-2013 04:33 PM #16
      Did all the normal stuff. Isolated the pump. Yes, I did the funnel trick both before and after the pump was messed with. It wouldn't pull a drop out of the funnel both before/after. I only could get the pump to fill by sucking fuel through it with a vac pump attached to the overflow/return hose. Guess I could try to find a banjo center-bolt from the inlet side and put on the return side just to see if it will move fuel but I don't think it will. Even if it did, what would that really prove if it still won't achieve "primary" pressure in the reservoir?

    17. Member
      Join Date
      Jun 18th, 2010
      Location
      sacramento,ca
      Posts
      801
      Vehicles
      1982 vw truck diesel, 79 rabbit 2 door diesel
      11-20-2013 04:43 PM #17
      so you did that stuff before you sent away the pump? was this a working pump that just quit all of a sudden?

      i hope you didn't pay this person to mess with your pump? you would have been better off buying a leaking pump from ebay or somebody on here that hasn't tampered with settings, and resealed/cleaned yourself.

      replacing parts, no bench test, not even taking a second to see if pump is moving fuel is crazy.

      i say do as i said above and cut your losses, and sell your pump for parts to somebody that can use it.


      take the time to do a new water pump/ timing belt/tensioner if applicable.


      i bought my current rabbit that this thing happened to, i ended up selling pump for parts. previous owner was so crazy he actually cut the exhaust off and switched the tank grasping for reasons why his pump wouldn't move fuel, didn't even think to try at the pump. lucky me

    18. 01-05-2014 09:59 PM #18
      Update on my problem rebuilt pump failing to prime:

      Short summary is : I WAS WRONG!

      Long story: Got the pump back to the guy who rebuilt it. He slapped it on an engine on a test-stand and the engine fired right up. He drained it again and sent it back to me. Not believing, I put the pump in a vise, rigged a fuel hose pulling out of a quart bottle, and spun it over with a speed-wrench. It shot fuel out the return port in maybe 10 revolutions. Installed it on my motor. It took a lot of cranking, for whatever reason, but it finally pumped the lines to the injectors full and started firing. Once it took off, all was good.

    19. Member 8v-of-fury's Avatar
      Join Date
      Jul 14th, 2008
      Location
      Central Ontario, Canada
      Posts
      3,705
      Vehicles
      Because MK1
      01-05-2014 11:05 PM #19
      Quote Originally Posted by dsl_lvr View Post
      Update on my problem rebuilt pump failing to prime:

      Short summary is : I WAS WRONG!

      Long story: Got the pump back to the guy who rebuilt it. He slapped it on an engine on a test-stand and the engine fired right up. He drained it again and sent it back to me. Not believing, I put the pump in a vise, rigged a fuel hose pulling out of a quart bottle, and spun it over with a speed-wrench. It shot fuel out the return port in maybe 10 revolutions. Installed it on my motor. It took a lot of cranking, for whatever reason, but it finally pumped the lines to the injectors full and started firing. Once it took off, all was good.
      Sooo... wth happened then. It all of the sudden started moving fuel for the rebuilder.. I hate that crap lol. with no explanation.

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •