How do I time the engine with an incorrect flywheel mark? - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• How do I time the engine with an incorrect flywheel mark? by dbird on 30 Oct, 2025 10:39
• Hello, I am having another issue with my 1981 Rabbit 1.6 NA Diesel that I can't seem to find a solution for on the Internet.
  
  I redid the clutch and it's associated parts recently, and I reused the old flywheel. I've heard a lot about pressure plates having the wrong holes on them, so I am assuming that I have put the flywheel on wrong. When the TDC mark on the flywheel is lined up with the notch on the bell housing, with everything else timed (cam, injection pump), when I turn the engine over slowly, I can definitely feel that the pistons are hitting the valves. I can move the crankshaft pulley about a quarter turn either way before they hit each other.
  
  I read somewhere that if you align the crankshaft pulley's dot with the VW logo and lined up the top, that would be TDC for the crankshaft. I tried that, there was no interference, so I tried starting it, and it kind of began to start, but it didn't get into idle. I just assume that this obviously didn't time it well, so I looked further into it, and someone mentioned that you can do the following:
  
  1. Set the camshaft to where there is a valve fully open on cylinder 1 (I'm not sure how to tell this, so if someone could help me with that please    )
  
  2.Turn the crank one way until pistons and valves make contact then mark that on the flywheel
  
  3. Turn the crank the other way until pistons/valves contact and mark that point as well
  
  4. And then apparently, "true TDC is EXACTLY between your two marks."
  
  I haven't tried this out yet, but I am just wondering how one could get exactly in-between those marks? I am really hoping this method works because I really do not want to pull the  head again and DEFINITELY not the transmission. If anyone could perhaps explain this method more in-depth if they know it, and how to find if one of the valves are fully open on cylinder 1, I would really appreciate the help. Or if anyone has any other method that doesn't require me to tear this engine apart again. I am so close to getting this car to start! I have been wrenching at this thing for months now! I will admit, I have learned a lot.
  
  As always, thank you guys for your help!
  
• #1 by ORCoaster on 30 Oct, 2025 19:46
• dbird,  I will see if I can help here.
  
  First I am going to make some assumptions and if they don't hold then we have to come back to a discussion.
  1. I assume you know that with the valve cover off and turning the crank so that the lobes of the #1 piston are straight across that you are at TDC or very close.
  
  Do that.
  
  2. I assume you know how to time the engine by removing the timing belt.
  
  With the lobes pointed as recommended, remove the timing belt.
  
  Now you should be able to rotate the camshaft pulley such that the #1 lobes of the cam point down, either one will do.  Lock that position somehow and you will have a valve in the fully open position.
  
  Now rotate the crank using a wrench on the nut in the front of the crank.  That will give you some movement until the piston touches the valve.  Mark the position on the flywheel with a Sharpie or some thing you can see in that hole.
  
  Now rotate the crank the other direction and do another mark on the flywheel. 
  
  3. I am assuming that there is going to be some sight distance down that hole and you will be able to see the flywheel and the marks as they come up.  You should be able to get a good idea of where 1/2 way is between the two.  Put some paint on that place.  I think you have a good start on TDC now. 
  
  Reset the cam to TDC #1 lobes to sideways position, Pin the IP through the hole, move the crank to the dotted TDC position and replace the belt.  Tighten the tensioner and rotate the crank through several revolutions to be sure it won't bump the valves with the piston. 
  
  Fire it up if all is well with the rotation check.   
• #2 by fatmobile on 01 Nov, 2025 11:17
•  The crank sprocket and pully dot should be at 7:30 when the engine is at TDC. If the keyway hasn't been repaired/moved.
   The flywheel mark should be close to lining up with the bellhousing pointer when the dot is at 7:30.
  That's 7:30 in relation to the block, not the world, since the block is slightly tilted.
  Not sure what you mean it's lined up with the VW logo or being at the top.
   
   Where is the flywheel mark when the sprocket/pully mark is at 7:30?
  
   I pull glow plug 4 and put a tube in it.
   The tube goes to a bottle of colored water as the piston goes down water is pulled into the clear tube.
   When turning the crank; at the top the water quits being pulled in and reverses.
• #3 by ORCoaster on 01 Nov, 2025 17:55
• I forgot about the water and tubing trick.  You have to have a long tube so you don’t get water in the cylinder.  Use a fitting in the GP hole that the tubing will fit tight on it .
• #4 by dbird on 05 Nov, 2025 08:51
• I really appreciate your guys' help, on this post and the rest of the forum.
  
  I was able to time the engine and start it up. It idles a little rough and shoots out white smoke from the tailpipe. I believe this is a symptom of improper injection pump timing, but I'm not sure if it is too retarded or advanced. I will try pulling the timing advance knob on the dashboard to see if it smoothens out the idle and clears the white smoke a little, at least. I have the block heater plugged in, but it is still around 40 deg. F where I live. Would adjusting the fuel enrichment screw do anything to solve this as well?
  
  I did actually have a question about the white smoke; I know that it as well as rough idle are sure symptoms of too retarded pump timing, however I did also read that oil/coolant getting in the combustion chamber could cause this. I know that isn't the case since I just replaced the head gasket, but before I put the head back on, I sprayed some Aerokroil on the cylinder walls, just to lubricate it. Could it be possible that this could be burning off? Just a rookie question.
  
  Thanks!
• #5 by fatmobile on 05 Nov, 2025 20:27
• People sometimes add oil to their diesel fuel.
   When it burns you don't notice a cloud.
   So other forms of oil in the combustion chamber don't really show as smoke.
   they burn like the diesel does.
   Pulling the cold start lever especially when it's cold and first started, is a great way to see if it the timing is retarded or too advanced.
  
   Too advanced and it works the starter too hard, slows the engine down
    I like to crank for a while and get it to fire a little before I pull the cold start lever because it can slow the engine down.
  
   I've heard of the fuel enrichment screw being turned out too far and the car wouldn't start.
   Best to mess with it while running because the idle screw will need turned too.
  Not a common problem and yours is actually running so that probably isn't the problem.
  
   Air in the fuel can also cause white smoke.
   But I'd check timing first.
• #6 by dbird on 06 Nov, 2025 18:20
• Put some fresh coolant in it after flushing the system... I know VW guys are anal about what coolant to use, I got Blue Prestone, on the bottle it says for VWs pre-1996.
  
  Anyway, I figured what the hell and let it run for about 8 or so minutes, totally smoking out the whole neighborhood. Eh, good mosquito repellent, right?  It started to idle pretty nice. It still jumped around a tiny bit, but it got better. I played with the timing knob on the dash, it seems like where I have the timing on the pump is fine. No matter where I set that knob, it still spews out white/grey smoke like a smoke machine at a haunted house. I did notice that injectors 3 & 4 are bubbling at the base of the injectors, like where they meet the block. I don't see any cracks, thank god. Not really sure what this means, if there's still air in the lines? I've got clear polyurethane and I don't see any bubbles. I cracked the injector lines at the top of the injectors and cranked it several  tmes before I started it. I also noticed that injector 3 is smoking a little bit. I believe fatmobile mentioned in another topic I started that if the glow plug light doesn't work, they will stay on no matter what the temp of the engine is. Let me know if I misunderstood what you meant.
• #7 by ORCoaster on 06 Nov, 2025 18:54
• dbird,  If you suspect poor timing just loosen the IP up but keep that one nut closest to the radiator tight.  Then start the engine.  Once it is running you can then loosen the nut and push the pump a little towards the engine and increase the timing.  If it runs worse than it was then pull on it towards the radiator.  That will retard the timing. 
  
  The bubbling at the base of the injectors is likely the diesel that came out of the top nut when you loosened them to get it started.  It seems to take a long time to boil it off.  Check the little hoses that are on the injectors to see if they are leaking fuel down.  You can put zip ties on those and tighten the hose that way. 
  
  The way I have my IP timed when I pull that Cold Start knob it increases the timing by about 2.5 degrees I believe.  Mine will increase the knocking sound as I have my pump timed to about 1.05mm.  It is a turbo with 155 bar injectors.  If you pull on the knob and nothing happens you probably can increase the timing.  Push IP towards the engine. 
  
  If I remember the fatmobile discussion on the GP staying on all the time it was about not having the sensor connected to the heat system.  That sensor tells the GP relay to stay off.  If the wire is disconnected the relay comes on all the time and so do the glow plugs.    So you may have misunderstood what he was trying to tell ya. 
  
  Keep at it.  Get it timed first then play with the idle and mixture screws.  Balance them out,  Higher amounts of fuel on the mixture screw means less bump on the idle and visa versa. 
  
  
  
• #8 by fatmobile on 07 Nov, 2025 08:41
•  Do you have a clear line coming from the pump (going back to the tank) too.
   Or just one from the filter to the pump?
  
  ORC is right. I was saying the glow plugs turn on every time you try to start it,
  if the glow plug temp sensor is unplugged. But they won't stay on.
  Good to know if there is a hot start problem caused by a weak starter.
  
   You said: " I played with the timing knob on the dash, it seems like where I have the timing on the pump is fine. No matter where I set that knob, it still spews out white/grey smoke like a smoke machine at a haunted house. "
  
   So it runs better with the cold start knob pulled?
  But still smokes white?
   I would try advancing it and see if that still occurs.
   I make a mark where the pump meets the bracket.
   Near where that top front mounting bolt is.
  Just a thin mark. I use a pointed razor blade and tap it into the metal.
   Then you can turn the top of the pump back toward the engine and see how far it moves.
   Like Hagar said just move it the width of a pencil line.
  
   You can also move the pump while it's running, like ORC said.
  When I do that I need to use vice grips to grab the metal bracket that holds the accel cable.
   There is a place with plenty of aluminum under it.
  I use the vice grips like a lever.
  I don't use the metal on top that the idle screw goes through, after breaking that once.
• #9 by ORCoaster on 08 Nov, 2025 17:35
• Ahh, when I read the reply from Fatmobile about pulling out the cold start knob I thought well you can pull or push that in all day long but if your timing is really off you still won’t know it.  Why? Because if you are off by more than a couple degrees you won’t get enough correction from pulling that knob.  You might not get any.
  
  The cable connects to a lever that has to be adjusted at the pump to be able to engage the cam that then pushes in on a piston that advances the timing. 
  
  
  When I have purchased used pumps that lever is so out of adjustment it does nothing but make you think it is advancing the timing.  The lever limits out before the cam engages. 
  
  
  I generally have taken the lever off. Then turned the cam until I feel it bump against the internal parts.  Then I put the lever on with the maximum amount of travel I can get when I pull on the cable. 
  
  
  Just so you know how it all works.
  
  
  And by chance are you using a dial gauge to set the timing?
• #10 by sgnimj96 on 26 Dec, 2025 16:02
• Just a reminder, if you adjust the IP position any with the lines tight,
    whenever you think you are done
  make sure you loosen all the nuts on the fuel pipes coming out
  of the injection pump to  relieve the tension on the 4 metal pipes.   
  Then tighten them back up like normal.
  Not doing so might cause the metal lines to crack later on.
  
• #11 by ORCoaster on 26 Dec, 2025 19:21
• Good reminder there.  I usually keep the lines loose ish when adjusting the timing with the dial gauge.  But if I have the engine running and using the Snap-on meter I do have to  go back and loosen them if I am changing the timing much more than a couple of degrees or so.
  
  I do have extra lines as I have extra pumps that go with them.  They come in handy when that #3 line decides it has had enough and pops a pin hole spraying diesel all under the hood and making it run like a dog.