Hall sender help needed.

[DuncanS]

Hold the phone here. The Hall effect sender triggers the spark and senses the timing. This signal is not a "batch" program. At 4k RPM, it has to happen for a given cylinder 33 times a second. And so for all 4 cylinders, the critical spark timing has to happen 136 times a second, all in the correct order within a couple of degrees of engine rotation. A single rotation at that RPM for a second is about 24,000 degrees. So to get the timing right within 3º means you have to have it right within one eight thousandths of a second, and tells us why a Hall spark trigger is far more precise than contacts and a condenser. This is no longer trivial shade tree engineering. I have no doubt I could build an engine from scratch which would run. But anything beyond this make and break wonder at more than 150 RPM would be a no go. Multiply that by a factor of 27 and you have an idea of what the Hall is busy doing down there under the rotor.

If it is possible to turn the eccentric tab drive at the bottom of the rotor shaft 180º when driving the pin back in, then I get it.

In fact I'm in on this wireless thing as it's one less bit to go wrong. Do you have a source for them that we can buy from?

Duncan

[DigiMatrix]

My point with the batch fuel injection was, if it was not then it could matter.

Let me ask this question. If you have 2 hall sensors mounted at 180 degrees and 4 identical Hall windows at 90 degrees from each other (this is what the Vanagon distributor has) - which Hall sensor would fire first? or would they both fire at the exact same time?

Maybe watch this - might help?
https://www.youtube.com/watch?v=WRxniD63mZA
_________________
_________________
'91 Syncro Westfalia
soon to be 2.5 liter stroker WBX 10:1 comp
Digifant ECU with knock sensor and custom
cylinder selective knock control by me

[ALIKA T3]

[DuncanS]

Good Lord. Dunce cap time for me again. What the _(*E$RTP(*T(&^R was I thinking? Of course!! For some reason, I saw the white blob and that triggered the notion there was only a single sender. Of course, there have to be four. The jury will disregard that entire line of questioning.

Sorry, Duncan

[DigiMatrix]

Hi Duncan, glad the light went on and glad you kept asking questions because that is how we learn. You were stuck thinking there was only one Hall window which is easy to do becasue those distributors do exist.
_________________
_________________
'91 Syncro Westfalia
soon to be 2.5 liter stroker WBX 10:1 comp
Digifant ECU with knock sensor and custom
cylinder selective knock control by me

[DuncanS]

Didn't know there were one Hall distributors. But it makes sense. All the commuter really needs to knows is crank location. If it knows how many cylinders there are and even if they aren't symmetrically placed, then it can do the rest.

But all of this comes down to what do I do? Currently have a Chinese POS dizzy. Don't want to do a tide-me-over solution. So how do I find a decent dizzy and then stick a wireless Hall sender inside it. Know how to put it in, I just don't know where to find it/them.

Duncan

[Captain Pike]

https://www.thesamba.com/vw/classifieds/detail.php?id=2251344
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_________________
LEARN TO SELF RESCUE
59 Panel bus, 1966 Single cab. 73' 181. 73 Westy. 91' H6 Vanagon 3.3L.
.....................All Current.......................

[hardway]

Other earlier VAG products had Hall sensors in distributors that had mechanical timing advance components. The Hall effect switch was mounted on the breaker plate which was rotated by the vacuum motor. So the switch needed flexible wires to it. But of course they were an additional point of failure. But Hall effect switches do fail. They fail reliably in BMW products. I have proven the failure on at least 12 different 2.1 Vanagon motors. I keep a spare distributor under the back seat in all of my buses. They fit in the box with the spare ECU.

[DuncanS]

[DigiMatrix]

Duncan, what you do is get a spare like shown below. Remove existing distrbutor by removing the single hold down nut on the clamp bracket (do not loosen the clamp part of the bracket). This will maintain the timing on the original distributor. Install the spare distributor and set the timing on it at home. Once done - remove the spare and re-install the original distributor - the timing won't have changed because you never loosened the clamp portion of the bracket that allows the distributor to rotate.

When you need to install the spare, as long as the clamp on the spare was never loosened it will still be set to the timing that you have already set at home.

_________________
_________________
'91 Syncro Westfalia
soon to be 2.5 liter stroker WBX 10:1 comp
Digifant ECU with knock sensor and custom
cylinder selective knock control by me

[DuncanS]

Not having a timing light--beddagedun--I was planing on making a jig using body putty to be a perfect match. It will have a disc which fits perfectly around the outside of the dizzy body and a tab which engages the Hall sender slot. A 24ish inch long pointer will be aligned with some spot in the engine bay. So when I get the new/old one, which will also get a replacement wireless sender, the new dizzy gets stuck in: align the pointer and tighten the clamp. Pull the new one and install the Hall. Remove the dead hall in the current one, install the second new hall and Bob's your Uncle.

So much controversy about how many degrees BTDC and all that stuff. But you are right, If I'm going to get to know this beast the way I should, then get the timing light and learn.

I've been spoiled as all the buses/vans I've had continuously since 1961:

have been either new or only a few years old. Now, it's an entirely different ball game.

[ALIKA T3]

I used to do the timing by ear revving the engine with the other hand.
I bought a nice adjustable timing light recently, the last 2 engines I checked I did by ear were dead on the money
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[plummerdesign]

Duncan...Did the issue find resolution?
Please DO TELL us how if so.

Cheers,
Jeffery : )
_________________
It is old and green and it makes me grin.
1984 Westfalia 1.9

[DuncanS]

Bought a new dizzy with the Hall installed from BD along with a spare clamp. Plan is to drill a pair of holes in the spare rotor cap while the existing dizzy is in place. Shove a rod through the holes so it lines up with something in the engine bay. Maybe about 14 inches long. Pull the dizzy and put in the new one. put on the cap with the rod and align it to THE spot. Tighten the dizzy down and put on the new cap.

However, I very worried that there are some intermittent bad spots in the ECU/engine harness, which may have used the Hall to fail, or is just bad in itself. For the most part, all the signs point to the harness being OK while testing, but I keep returning to the question of why I was able to "fix" the problem once for a couple of weeks, by just running my hands over the harness. So, I'm worried that if there is a corrupted harness, it may damage the new Hall sender.

With all this in mind, I am preparing a donor harness swap. I've checked all the continuity in the donor and it seems OK and is about ready for the switch.

However, in all the handling of the donor, how do I know if I might have damaged some of the 34ish YO wires and terminals?

Unless someone tells me there is almost no way the Hall could be ruined, then I'm inclined to toss in the new dizzy and see what happens.

I remember the adage, in trying to diagnose a problem, never make more than one change at a time.

Duncan

[dobryan]

You’ll quickly find that the rod never moves. The rotor does not set the timing. You rotate the distributor body around the rotor to set timing. Not the other way around.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[DuncanS]

Dob--That's the whole point. I don't want the rod to move. That's how I will do the timing set up. If the rod points to a spot where the dizzy has been set for the last three years, then that's the correct timing. So when I put the new dizzy in, if I rotate it until the rod is in the same location, I will have duplicated the position for the new one.

Woke up with a thought this morning. Since I plan to put in a new or rebuilt harness--different one--why not just temporarily abandon all the dizzy leads and bypass them. So the first step will be cut the leads at the dizzy plug with enough length to splice some lamp cord in and also the leads near the ECU plug. Then run lamp cord from the existing dizzy plug to the proper wires at the ECU plug, along with another from the center wire Hall plug to the ICSU pin 17. This will isolate the dizzy wiring from the existing harness. If the engine runs, then it wasn't the dizzy after all. If it doesn't run, toss in the new dizzy and try again. If it runs, then it was the old dizzy which was bad.............maybe. It could have ben a combo of both the wires and the dizzy. And if it still doesn't run, the the harness HAS to be changed.

Then, get my act together before going off on any of the other happy 27k projects, and get the replacement harness installed.

Duncan

[DanHoug]

[DuncanS]

A timing light? OK. I'll set up a laser mounted on the A/C housing to shine down on the engine bay and organize it so it hits the end of the rod. I'm assuming that's what you meant.

Seriously, you're right, but for now I'll just use the rod method as I want two dizzies set up with the clamp in the right position so if one fails, then I just drop in the new one and off I go. The car has beeping great................until it wasn't. It was getting 22MPG on the highway, so whatever there dizzy setting is, it's what I want to keep.

I'll send pics of the Rube Goldberg timing "light". Be prepared for not you normal timing light.

Duncan

[DanHoug]

when you buy one, get an 'advance' timing light. that makes it really easy to find out what the total advance of your sweet running timing setting is so that you can replicate from here to eternity. no jiggedys needed.
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[dobryan]

Duncan help me understand what the rod that is locked on the rotor does. The rotor only moves when the engine rotates, not when the distributor is rotated/adjusted.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794