81 rabbit injector line issue

[81DubDiesel]

Hey, guys!
New guy to the forum here! Let me start of by telling you a little about myself. My name is Nick and I have been around Volkswagens my whole life. (Mostly air cooled) I got the chance to buy my 1981 Rabbit Diesel LS with 80,000 original miles for a great deal and decided to jump on it. I have had the car for about 6-7 months now and haven't had any huge issues with it until now.

Now to the issues. Starting about 3 months ago I have been breaking my #3 injector line. I have replcaced it three times now. The last time it cracked I knew there must be an issue with something. I read that I'm either missing a bolt on the injector pump, 'missing a bracket or a motor mount is bad, as those are the usual suspects. I compared my car with my buddies 81 diesel L and saw that I am, in fact, missing the bolt on the drivers side of the pump under the injector lines and I'm missing the bracket that holds all 4 lines together. I still have the two up top though. That's the first main issue. The second is that I went to put the new line on my car so I could move it out of the driveway while I waited for my new bracket to come in. I put the line on and now when I rev the car it makes a horrendous knocking noise but it sounds fine at idle. I did some research and found out it is a noise called "nailing." Correct me if I'm wrong. Now my question is what would cause this? The only thing I did was replace the number 3 line. Did some dirt get in the line and maybe clog the injector?

Thanks for your help. I look forward to using this forum and connecting with diesel lovers around the world.

-Nick

[ORCoaster]

Sounds like a dirty injector to me.  Give it a little bit more idle time and rev it again some.  I generally don't hear it after the first few times. 

[81DubDiesel]

Thanks for the input. I will let it idle a little longer today and see what happens. I didn't want to run it too long in case it was a bigger issue. I also think I have a crack the the nipple of the hard return line and it likes to drip out when I have the return hose on it. Is there any way to put maybe a tighter hose on it or should I just go ahead and replace the whole injector?

[81DubDiesel]

Update:
I just eat it run for 5 minutes or so and it was puffin some white smoke and smelt pretty bad and the knocking didn't seem to go away at all the time it was running and I kept giving it revs every few minutes. I unscrewd the injector line form cylinder 3 and decided to rev it and the car stopped making th noise as I reved it up. Bad/dirty injector at that point, right?

[air-cooled or diesel]

you need to clean that injector, perhaps a new injector, or nozzle assy., then when you get that one right, dump a can of lubro moloy into fuel tank, fill it up. run it like you want to clean it.

[ORCoaster]

You might just get away with snipping the last 1/4 inch of the rubber return line off and pushing it on the nipple.  Once you have it bottomed out give a short tug up on it and that will help seat it tight.  Only can do if the line is long enough to reach to next injector.  If not hit the motorcycle shop for some of the right diameter line.  Clear is best as you can see if you have air in the system that way.

Just some hints for the new guy.

[81DubDiesel]

Awesome. I appreciate the help, guys. I'll pull the injector out and clean it tomorrow. Any tips on how to clean it or getting it off? Also does anyone have any info on what side that injector pump bolt would be? Drivers side right under the lines. Thanks again.

[ORCoaster]

When I pull the injectors out to do a compression test I just undo the nuts on the injectors and the ones on the pump and lift the set of lines out of the way.  At times I have just undone the nut on the injectors and the keepers that hold all the lines together and just loosen the nuts on the pump.  But then it always seems more of a struggle than to just get them out of there altogether.

Now to get the injector out you need a 27 mm socket, a good medium size extension and a breaker bar.  Preferably 1/2 in.  Soak the injectors for a couple of days with penetrating oil or ATF.  You don't want to just start unscrewing them if this is your first rodeo with them. They may not have been removed and coated with anti_seize and be a bearcat to get out.

Always turn or put pressure towards the head when loosening or tightening.  Don't ever pull towards the front of the engine.  That head is only aluminum and you risk snapping that front lip off the block if you pull.  Push towards the head. Get right in line with the edge of the block and keep the socket and extension vertically in line with the injector and push with you right arm in a sharp snapping movement.

You will need to reshape the heat shield once the injector is out as well so have a ball bearing, a pair of vice grips and a collar or socket handy and look up the process here on the site.  I think there is currently something going on discussing it.  Otherwise search for heatshield and see what comes up.

To get the two halves apart I put the top in a vise and use the socket to snap them apart.  Again soaking with oil for days prior will aid you in this venture.  Once I have them loosened I take it out of the vice and carefully take it apart in a very clean area.  I put down a clean towel or something to put parts on.  What ever is making that thing go clack is probably not going to be very visible to your eye.  We are talking microns big here.  I wash all those internal parts down with diesel or spray with air to make them clean enough to put back together. 

I use a 1/2 in torque wrench to put the halves together and to make sure they are tight enough once back in the head.  Do you have a Bentley manual yet.  This process is in there and so are the specs for torque.  If you plan to work on this car you will need one so start looking on line for one.  Craigslist has them all the time.  Just get the year and model of car you have. 

Best of luck on this. 

[air-cooled or diesel]

^or just get a new set of heat shields and put on in--
you may find you need a new injector or at the least a new nozzle assy.
but cleaning is a good start, to verify get 'pop' tested.(costs some to do)
 

[air-cooled or diesel]

Starting about 3 months ago I have been breaking my #3 injector line. I have replcaced it three times now. The last time it cracked I knew there must be an issue with something. I read that I'm either missing a bolt on the injector pump, 'missing a bracket or a motor mount is bad, as those are the usual suspects.

so one thing quick; the bolt your missing, if its the body thru bolt; mine are torks bolts, theyre special, hard find locally, a shop that does metric diesel pumps, or bosch, go online, i do believe theyre germany. get it

being your busting line#3 and its the injector/cylinder, looks like, your having problem at. if your busting multiple lines, imagine what your doing in cylinder. id be inclined, right now, swap in a new good injector, if you do decide to rebuild that injector, id test, i havent heard inj body going bad,,yet. but id test. a good injector may well, and easily solve problem.

[ORCoaster]

Why not just cut a piece of 3/16 or 1/4 inch fuel line and place it around the lines and clamp them with the metal parts.  Maybe you need something a little thinner walled so that might just be washer fluid line.  Anything in there, hose, cork, old sock that absorbs the shock should do. 

[TylerDurden]

Info on bolt and cone-nut here:
http://vwdiesel.net/forum/index.php/topic,33761.msg317832.html#msg317832

Diagram a couple of posts down.

[81DubDiesel]

Update for you guys!

I splurged and bought a new injector from Parts Place along with new brackets and replaced the missing bolt to the injector pump and the car is back to running great again. Thanks for all the help you guys. This forum is awesome. Anyway to rep the site? Stickers, shirts, etc..? I would totally be down with that.