'83 Quantum TD runs away (but then comes back) - page 2 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• #15 by Ortho Stice on 24 Aug, 2014 16:32
• Quote from: theman53 on 24 Aug, 2014 14:04

  How about just keep trying to get it running and work the air out of it.
  

  
  Precisely what I ended up doing. After standing there confused for awhile, I thought, "hey, why not force feed this pump?" and so I grabbed one of the raptors we have lying around the shop and fed it diesel straight from the can at the lowest psi the raptor can do (should be around 7-10 I think). Anyway it fired right up but not in the nice, steady idle way that it used to but with much drama and clattering and sturm und drang.
  
  So now, it starts right up but idles at, if I had to guess, between 1500-2000 rpms and throttle input does absolutely nothing. There was an actual pile of soot behind the exhaust after this drama. Okay so, my thoughts are this:
  
  -Is the feed pump somehow throwing stuff off? I'll check tomorrow when I try to run it off the tank in the car (ran out of time tonight).
  -Did I somehow slip the belt on the crank pulley when putting the new pump on? The pump and cam are lined up as they should be, but I didn't check the crank figuring that it would be unlikely to move as I was working up top. Again, something I'll check tomorrow.
  -I noticed that the anti-tamper collar on the max-fuel screw is missing from this pump; though it ran fine on the previous car, is it possible I need to pull back the fueling or something?
  -Is the pump in need of serious advance or retard?
  
  Like I said, experimentation will continue tomorrow. Thanks to y'all for being a springboard upon which I may bounce ideas.
• #16 by Ortho Stice on 27 Aug, 2014 12:01
• Okay, I've answered all my questions:
  
  -No, the feed pump wasn't throwing anything off. I hooked it back up to the car's tank and it did the same thing.
  -Nope, checked the flywheel timing mark and with the crank at TDC, the pump and cam are where they ought to be.
  -Max fuel screw does nothing. All the way in, no change at all.
  -Nope.
  
  So it looks I have two bad pumps, though bad in different ways. As such, I plan to rebuild the original pump as it (at least) ran the motor. Hopefully in disassembling, cleaning, and rebuilding I can figure out what was sticking and causing it to run away.
  
  Any suggestions on rebuild kits or is one as good as the other?
• #17 by theman53 on 27 Aug, 2014 12:13
• You make little adjustments to the max fuel. If you ran it all the way in you went the wrong way, back it out past where you had it.
• #18 by Ortho Stice on 29 Sep, 2014 16:14
• Say gents, any recommendations on a rebuild kit for these pumps? It is definitely the case that neither of these pumps work as is right now so I'd like to rebuild my original pump and put it back on. Strangely, I can't seem to find a rebuild kit or something like that from my usual parts sources...
• #19 by fatmobile on 29 Sep, 2014 19:31
• Try reindexing the accel lever to the shaft.
   One notch toward a little more fuel.
• #20 by Kraftwerk on 21 Dec, 2014 16:54
• Did you ever realized what was going on? Have similar simptoms on my '87 QSW TD...
• #21 by Ortho Stice on 15 May, 2015 19:42
• Quote from: Kraftwerk on 21 Dec, 2014 16:54

  Did you ever realized what was going on? Have similar simptoms on my '87 QSW TD...
  

  
  Hey sorry got wrapped up in other things (namely a $600 TDI Passat and my 300k mile 940). Well in short, sort of. I rebuilt the pump and it stopped running away. The little triangle weights that spin with the shaft were covered in weird surface rust / chemical scale or something. I took very fine sandpaper and rubbed all of that stuff off. I assumed that the crud was causing them to stick or something? Nothing else inside seemed as affected by rust.
  
  Sadly, when I put it all back together I clicked the starter with the ip lock pin still in place... that sheared teeth off the belt and now I have terrible compression. It starts and runs but once you try and rev it it begins misfiring and smoking and generally sounding terrible. I assume one or more of the valves caught a piston after top and bottom came out of time with one another.
  
  Also, and I wonder if anyone else has ever seen this: the injection pump pushed the seal for the top of the pump THROUGH the side of the top of the pump. Like broke a sliver of metal off and pushed its way through. Thankfully I have another pump head lying around, but damn. It's one thing after another with this car!
• #22 by fatmobile on 10 Jul, 2015 14:08
• I've had that top seal break the side off the lid,.. when I didn't trim the bumps in the seal enough.