TheSamba.com Forums
 
  View original topic: Wiring for factory electronic ignition (79CA system)
airkooledchris Fri Jan 23, 2015 1:41 pm

Because im *still* waiting 7 months later for my distributor to be returned by Philbin, I have started wiring back up the factory electronic ignition system on my 79 CA model with a spare distributor from a forum member.

There are 3 wires coming from it, outside of the connection to the distributor body. One of them is green, which goes to the special Coil. One of them is brown which ive connected to the grounding spade below the 3/4 intake runner.

The remaining wire is black, which I believe goes to that little connection hanging from the bottom of the double relay. At least, that's what it looks like it's supposed to connect to when checking the wiring diagram.

Can anyone with this system confirm this is the correct setup for the factory electronic ignition system?


When im trying to start it it just cranks and cranks, but if I try and give it a little gas at the same time it sounds like something isn't quite right. it wants to die right away as soon as I begin pressing the pedal.

Randy in Maine Fri Jan 23, 2015 2:13 pm

I was thinking that mine were plugged into a Meyle ignition module from the distributor via a little cable.

airkooledchris Fri Jan 23, 2015 2:53 pm





Indeed, there is a cable going from the Ignition Control Unit mounted on the firewall to the distributor. In addition to that cable, the loom leading out of the Ignition Control Unit has 3 addition wires.

Brown is ground, I got that and it's connected.
Green goes to the special coil, which ive got.

Black looks like it goes to the little wire that dangles out of the bottom of the double relay. I think the pic above confirms this in the factory wiring diagram, but I was hoping to get confirmation from someone who's actively using this setup currently.

I gave it a little gas while trying to crank again and it backfired and then there was smoke in the engine compartment. At this point im just going to back up to the original distributor and coil and just confirm everything will still fire up and run without issues, then go back to troubleshooting this.

I haven't had the electronic ignition system running since my overhaul last summer/fall. Part of that process was adding a second battery and a bunch of stuff for automatically switching power (ACR) - and im worried that some part of this setup may not be agreeing with the electronic ignition.

tristessa Fri Jan 23, 2015 8:03 pm

Green to coil - (#1), brown to ground, black to switched power, which I usually pick up from coil + (#15).

airkooledchris Mon Jan 26, 2015 4:42 pm


(yes I shot the video in portrait mode, I can't seem to get that through my head when I know it's to share online.)


This is what happens when I try to start the bus with the electronic ignition connected. It really has me stumped.

Note that in the beginning of the video I crank it without the key switching on the ignition. All im doing is turning the motor with the starter - and it sounds normal/fine when you crank it.

When I turn on the ignition and crank it, it will crank a bit and then grind to a halt and then crank again.

Note that about the 20 second mark there is a small ignition in the vacuum line even that produces smoke. It did this if I tried to press on the throttle at all while cranking (with ignition on)


Here's a little screenshot of that moment in the video, for your amusement:



I put the original distributor and coil back in, fired it right back up like nothing ever happened and it's driving great again.

I'm totally stumped on WTF would be causing it to behave this way from a simple electronic ignition system. It's stock to the vehicle for crying out loud.


What changed since it last worked on this bus:
Wiring harness, including the electronic ignition harness was rebuilt by Kyle
The distributor is a different unit than the one I was running before. It is a 79 California specific distributor in seemingly good shape though. The vacuum can holds vacuum on both ports.
Installed a bunch of Blue Sea components for the dual battery system. Fuses, relays/etc.

What direction should I be looking in to solve this? baffled.

gliderman Mon Jan 26, 2015 5:51 pm

Not sure what the timing differences are between the different distributors you are using, however, this seems to be a clear-cut example of your timing being too far advanced causing ignition to occur before the the piston reaches TDC. This pre-ignition causes the starter to stop momentarily because it doesn't have enough power to overcome ignition energy. Ignition occurring before the intake valve is closed causes backfire through the induction system.

Try retarding your timing a bit, until you can get the engine to turn over normally, then when you get it to run, hook up your strobe and time it according to the specs for the distributor configuration you are using.

The good news is that your starter sounds pretty healthy :)

airschooled Mon Jan 26, 2015 8:39 pm

gliderman wrote: Not sure what the timing differences are between the different distributors you are using, however, this seems to be a clear-cut example of your timing being too far advanced causing ignition to occur before the the piston reaches TDC.

x2. What is the factory method for static timing that setup? Is there one?

Wasted youth Mon Jan 26, 2015 8:49 pm

You said you "...put the original distributor and coil back in, fired it right back up like nothing ever happened and it's driving great again."

Could you elaborate a little? Like original, as in stock OEM, or as in the old one you had on there before you refreshed the engine. Which model distributor is it, and does it have points or an electronic module like your 79 system, or like the aftermarket module a lot of people use?

Did you actually static time this when you changed distributors or what?

airkooledchris Mon Jan 26, 2015 9:15 pm

Wasted youth wrote: You said you "...put the original distributor and coil back in, fired it right back up like nothing ever happened and it's driving great again."

Could you elaborate a little? Like original, as in stock OEM, or as in the old one you had on there before you refreshed the engine. Which model distributor is it, and does it have points or an electronic module like your 79 system, or like the aftermarket module a lot of people use?

Did you actually static time this when you changed distributors or what?

I didn't static time it. Ive never static timed a T4. I generally know where the distributor should 'sit' based on where it's vacuum can is in relation to the breather tower bail is.


When I said I 'put the original distributor and coil back in' - I should have clarified. I put the Federal distributor and coil back in. The 79CA one that I had in there before, and what I was trying to install in it again, has factory electronic ignition.

I guess the hesitation to crank (due possibly to the pre-tdc detination) just really threw me off the path, and made me go running back to the Federal version with points just to be sure nothing is screwed up otherwise.

Now that I know it'll run fine if I need to go back to the Federal setup, ill take another crack at getting the 79CA specific setup with it's special coil and electronic ignition working again.

Perhaps static timing it is something I should be doing. Ive just been lucky I guess as previously I would just throw the distributor in there and get it close to where I think it should be - then once running id set the timing where it needed to be.

one important lesson I also learned here was about having the correct coil. I forgot to take out the CA79 specific coil when I first swapped the Federal distributor back in and burned up the points in a few minutes. actually, the points themselves were OK, but the rubbing block melted away to nothing. I was watching the dwell meter and the number kept getting bigger and bigger until the motor died. doh :shock:

airschooled Mon Jan 26, 2015 9:19 pm

When I change distributors (to avoid embossments like this :lol: ) I always set the engine to TDC #1. I then KNOW that the rotor is pointing to the #1 plug wire, then I can get it close enough to start without static timing.

So if your engine is running now with the the federal setup, spin it to TDC #1, and swap in the electronic Hall effect CA setup one more time. Forget about the vacuum can, just make the rotor point to #1's plug wire and give it a shot. Dynamically time it from there.

I asked about static timing, because I don't know of a way to do it with electronic ignition. Points are easy to hear "click" when you leave the key on and turn the distributor. Of course, you would have to turn off the Dead and get the dog to stop barking…

Robbie

airkooledchris Tue Jul 07, 2015 1:50 pm

In case anyone here is curious, I am STILL trying to get someone at Philbin to send me my distributor back. Ive worked with Tony, who does most of the work on the VW distributors, as well as Joe who is usually at the front desk.


If you can get yours rebuilt anywhere else - do so. It's been over a year now.

airkooledchris Tue Sep 08, 2015 3:39 pm

I am still trying to get them to send me my distributor back, if anyone is keeping score.

A month ago Tony said they would have the last needed part and would have it back together and shipped shortly. When I called today he said he has the part and will try to finish it up this week.

Every time im told someone will call me back with an update, but have never received a single phone call from them. I end up waiting double the time they said it would take before I call again, only to find out 'it's one more week' again.

Tcash Tue Sep 08, 2015 9:25 pm

Post some feedback.
http://www.thesamba.com/vw/forum/viewtopic.php?t=71850
Tcash



Powered by phpBB © 2001, 2005 phpBB Group