Help me troubleshoot acvw no spark

You do know that #1 is the cylinder on the passenger side closest to the transmission, right?

It can be non-obvious that the front of the engine is the front of the car, not the belt end.  It trips me up every time, for sure.

And let's not get started on the times I got the wires wrong on Hondas because my right side engine centric brain ordered the plugs left to right, not right to left.

Yep, my tins even have the cylinder number by the plugs.  
 

in the interest of "what's the worst that can happen" I ordered an electronic ignition module from one of the vw suppliers that has excellent ratings and reviews.  
 

nothing sounds mechanically wonky when cranking and spinning by hand definitely gives 4 compression strokes that are hard to spin past if I don't let it bleed off, so I'm hoping we're just that close and need to get rid of some old parts.  

Knowing how the stuff works is helpful.  This thread has already covered some of it:

Power to coil positive is constant whenever the key is on (but whether it is as much voltage as it is supposed to be, you have to verify).

The connection from coil negative to ground goes into the distributor, through the points when they are touching, and into the distributor body which SHOULD be grounded but may not be, or not very well (again, something to verify).

The ignition coil produces high voltage when the ground is taken away from it or opened. A lot of people don't know that. Current must flow through the coil long enough to 'grow' the magnetic field inside the coil. When the circuit is interrupted, the magnetic field collapses, moving very quickly across a set of windings inside the coil which induces voltage inside it. 

The thing that's important about that that hasn't been mentioned is the adjustment of the points. Just because they are touching doesn't mean they're working. For one thing, the surfaces can get ugly. I run fine sandpaper/emory clotch between them occasionally. But the other thing is that they can touch too briefly to give the coil sufficient time to reach magnetic 'saturation' or a fully grown magnetic field.  Since the points are spring loaded, adjusting them closer or further isn't just to make sure they touch at all, it also determines how long (how many degrees of distributor rotation) they stay touching. That's called the 'dwell' time and if it's too brief the coil will not create enough voltage to get a reliable spark.  So, check the gap on your points (which by extension is verifying the dwell time). 

The condenser... exists?! Any time you turn off an electromagnet, that quickly collapsing magnetic field crosses the wires that made it and induces a voltage back onto it. So when you turn off an electromagnet, the voltage goes UP (briefly). The condenser is a capacitor that essentially 'eats' or rapidly converts that voltage spike into a stored charge which is then discharged slowly when the points connect again. The point of doing that is that it shortens and weakens the spark/arc which occurs at the points when they touch and separate from each other, which decreases wear on the points.

The coil itself can also be bad or mismatched. If you can find the specs for it you can measure the resistance of the coils two circuits. The 12v circuit (called primary winding) is usually low single digit ohms, sometimes barely over 1 ohm. The high voltage circuit (called the secondary winding) has a ton of small wire in it and usually has something from 8-20 thousand ohms. To check resistance you much touch two points. The not-obvious thing about the secondary winding is that aside from the obvious hole where you put your coil wire, the other point you should touch is just one of the primary winding terminals. The secondary circuit is T-d into the primary circuit and it doesn't even really matter which terminal you measure from (coil positive or negative) because the primary has only a few ohms of resistance which makes no difference in a sea of 10,000 ohms.  Even if you don't know what the specs are, this allows you to identify big outliers like coil primary having 20, 30 ohms or coil secondary having 900 ohms or 60,000 etc. The fact that you have spark somewhere, sometime suggests the coil 'works', but again how well? It doesn't hurt to do the tests.

So, check point gap, point surfaces, ohms from points to battery ground. Check actual voltage at coil positive while cranking.  If the spark is getting into the distributor but not back out of it, you most likely have a problem where the electrical contact point in the center of the distributor rotor connects to the center of the inside of the distributor cap, or a problem at the other end of the rotor where it jumps across to the terminals around edge of distributor cap. The coil has to make TWO simultaneous sparks in a distributor system (one from rotor to cap and another at the spark plug), another thing a lot of people don't realize. So if you can get one spark (a spark tester, or holding coil wire near a ground)  but cant get TWO sparks (ie spark at the plug end of the plug wires coming out of the distributor) that may all relate back to the coil not making sufficient voltage because the dwell/points adjustment is wrong, or there's low voltage into the primary circuit, or the ohms from coil ground to battery negative are high because of a bad connection somewhere.

I did clean the "new" points with my point file.  Yep, i have a point file.  I just haven't messed with points much since my teens.  When i put them in i also set to spec(.015).  Also measured the resistance across the coil +/- at 4ohms which is in spec as well as measuring the resistance from + to the coil to cap lead and I don't recall the number but it was within specs.  I have 2 other coils that measure similarly as well.  
 

it took a while to get it back but i do understand the theory, and i kept working backwards until I had good strong spark, but now it's gone and it's frustrating.  
 

i have not rechecked the coil resistance since i realized spark was gone.  It's on the to-do list.  It was a new in box unit, but that doesn't mean much.  

New parts are unproven.  I've had more than one new part be dead on arrival 

Are the lobes of the distributor in good shape? Not worn down too much.  I don't remember if you changed it out.

Also there is an anti chatter spring at the bottom of the distributor. If it's missing I believe the shaft will move up and down on and off the worn section of the lobes causing intermittent spark if the lobes are worn in the " normal" position 

Edit: I'm curious to know what you don't like about pertronix electric ignition? I've been using it on my 914 for years without issue.

Well, hopefully long after you've fixed your issue someone that knows less will come along and find my post useful. lol.   I just got done fighting the ignition on a 71 Plymouth we're working on, so i relate. I ended up converting it to electronic ignition with a distributor from a newer engine and an ignition module from a GM HEI that i wired in. 

Are your valves too tight or misadjusted?

I had a rotor that was berkeleyed out of the box.  Took many hours to figure out since I installed new points, condenser, cap, rotor, plug wires, and plugs.

Also bought a bad cap.  The center carbon contact was too short. Car ran with it installed... sort of...

I've tried every combo of new bits and cleaned up used ones that were still decent.  Also verified the coil is functioning by sticking it on my wheel horse and firing the tractor up.  I think I'm taking today away from it, and maybe the next several.  The engine was bought whole as removed from a van, after sitting on a garage floor for half a dozen years.  Distributor lobes look good and no different than either the 914 one or the older cast iron one.  The one in the engine is a bosch 009.

....Will it run on starting fluid?

No, 2 cans later 

It seems like you have checked everything electrical (unless there is an intermittent in the wiring somewhere). Is everything good in the distributor drive? Is it holding at hand crank speeds but slipping/skipping at engine crank speeds? Sorry if you hit this already and I missed it.

The distributor spins nice and smooth with cranking.  The wiring and ignition switch were done yesterday morning, i guess I could remove them from the equation with a jumper to the coil from the battery, but i have steady battery voltage at the coil so i doubt there's an issue.  Plus it's literally 8 feet of wire between the switch and coil with no interruptions 

In reply to Patrick (Forum Supporter) :

Now we are looking at the rotor and the cap

Wait, I'm a little confused here.

Have you actually checked for spark at the spark plug ?

   Vigo,  good post.

The simpler they are the harder they are to diagnose.  No computer needed here.  Just a few old farts who have been through it before.

1. Condensor is not needed to get it running.  It just makes points last longer.  Remove it for now.

2. Is the rotor spinning when the engine is turned over? Stupid but basic question.  

3. Put a plug wire in the coil, and connect a plug. Ground the threads of the plug.  With the ignition on and points closed use a screwdriver to open the points, then close.  You should see a spark.

4. Often for the unlucky you are 180 degrees out of phase. Once you can generate a spark, put the rotor and cap on and flip wires 1 and 3 then 2 and 4.

Don't give up, others have been there too and very few set the car on fire or sold it for $5.

Yes i did check for spark at the plugs.  There was none, then i replaced the points(and cleaned/set to spec) and condenser and there was, now there is not again.  In the middle while there was i felt like i was getting close to a start, now we're back to nothing.

when we did have spark and poofs of almost firing, I switched the wires on the cap (1-3 and 2-4) to rule out 180* out and it cranked with no indication of attempting to run.  
 

I really don't want to look at it today.  My back is pretty angry and i need to carry a marble double sink top to the 2nd floor tomorrow.  
 

can a vw distributor only be installed correct or 180 out?  I'm used to chevy stuff where you can be any number of like 10 ways wrong if you don't mesh the gears right.  

It's been 25 years since I messed with them, but I think that you can install them incorrectly and out of time.

Patrick (Forum Supporter) said:

 

can a vw distributor only be installed correct or 180 out?  I'm used to chevy stuff where you can be any number of like 10 ways wrong if you don't mesh the gears right.  

 

 

Forgive me if I repeat something or tell you the obvious.

The distributor has an offset key at the drive in the block so it inserts in only one way. It is in correctly and seated when you can not turn the rotor shaft with your fingers.

There is a very thin cut line on the top edge of the distributor that I line up the rotor once it's inserted and TDC is set for #1 cylinder. 

In this pic that small mark for #1 is just left of the rotor or at 11:00. This will differ slightly depending on where my timing is set. Note the cooling fan is at 9:00 for reference.

edit: Following these marks with #1 at tdc gets me close enough to start the engine.

I could be wrong, the distributor only fits one way into the offset slot. BUT the slot is driven by the crank, and it can be put in wrong.  I would break this issue into two elements: get a nice fat spark and then get the timing right.  Set #1 to TDC, pull the dist out and wire the body to ground.  Spin the dist shaft and see if a spark happens once every 360 degrees to a plug from the cap.  This will verify that you are getting a decent spark and can move to get all the timing elements right.  

Couple more hours on your knees praying to the ACVW gods and it will all be good.  Just remember how tough it would be without the internet and a bunch of other fools telling you what to do!

One other thought.  Is the engine turning in the correct direction?

I have run into this with Bosch starters before.  They'll make a left hand and right hand rotation starter for different applications, using the same case.

Friend of mine picked up a 944 cheap that didn't start because the PO put in a junkyard starter that looked right but rotated the wrong way.

Ok, did you use a point file or sandpaper to clean the points?

Several times, I've had a bit of grit stick to the points and not allow them to close, causing no-spark.

Hold them open with a screwdriver and give them a blast of cleaner, then wipe the points clean with a cloth to ensure you are getting proper contact.

Here's the current situation.

points good.  Clean(with point file), set at .015.  Voltage at + of coil.  Test light flashes great to coil-.  Spark plug hooked to wire off coil held to ground sparks great(and tingles when you reach to hold the plug and turn the key).  Spark plug to any wire off the cap held to ground does not spark.  
 

when timing mark is around 0 on the pulley/fan, i can stick screwdriver in #1 hole and verify piston is there, at that point the rotor is pointing at what the interwebs diagrams tell me is number one, at the back of the car just past the vacuum advance canister.  To set it close, like pete told me, i turn the distributor until the test light just comes on indicating spark for number one.  The contact from coil terminal in cap to rotor is touching in the center, i can see witness marks.

to me it's screaming at cap and or rotor at this point.  

Hmmmmm.......

Yes it sure does.

Is there any track mark evidence to suggest that the rotor is grounding straight down through its center to the distributor?  Seen that one once or twice.