[NikiSpider]

Bought the centerline electronic distributor ID405 and the bosch blue coil for my 78 Alfa Spider and wired it up right but when I attempted to start there was a clicking/ticking sound coming from distributor and it started smoking. The spark plug wires are correct and the coil is wired correctly both from the car and the distributor. So I am at a loss. Any ideas? Is there a possibility that the distributor was wired incorrectly out of the factory i.e. black is red and red is black? I don't have the guts to switch them around so I thought if it's not fried yet, which is quite possible, I don't want to fry it.

Thanks in advance,

George

 

[JoeCab]

There are only a few possibilities I can think of that would cause the symptoms you describe.

1) There is something physical making contact inside the distributor causing ticking noise and smoking > Please pull the cap off and check that the rotor can turn freely without any obstructions, and that the rotor is fully seated and the black dust shield is seated as well.

2) The module is defective (overheating), hence noise and smoking. This is a very rare failure mode. You wouldn't expect this right at start-up.

3) The module is wired to the car backwards, which happens more often that you would think. Double, triple check the terminals on the coil that you have connected the + and - leads to.

We individually spark test each distributor before shipping them out, so it is unlikely that the module could be "wired wrong" internally - i.e. the positive and negative reversed inside the module as they would not pass testing that way.

Let me know if there is anything else I can help with for troubleshooting this situation.

 

[NikiSpider]

Hello JoeCab and thanks for the quick reply.

I have just triple checked the wiring. The red is connected to positive and the black is connected to negative to the bosch blue coil which has clear + and - markings. Also, I checked the Alfa wires running to the coil (green/black and solid green) and made sure they are connected correctly to the coil. Green/black is the positive showing 12 volts with a voltmeter. Also, I've taken off the cap and the dust shield is in place and the rotor is pushed down all the way and seated correctly. TDC is found and rotor is pointing to first lead. I cranked the motor and the rotor turns freely. Looks like we are left option 2: defective module....which is just my bleeping luck. I guess I'll be talking to you or Ian on monday for a return.

Unless there is anything else I should check?

Thanks again,

George

 

[kcabpilot]

I purchased an ID405 about 8 years ago and had a similar problem. It began when I was installing the distributor, I dropped the rotor and it broke into two pieces. So I ordered a replacement and what I got was an aftermarket rotor (not a Bosch part) can't remember the brand but it's a common one that you will get from either Centerline or IAP.

Anyway, the fit wasn't quite right and it ended up chewing up the inside of the cap. I actually took a picture of the original Bosch rotor and the aftermarket one side by side and could see that it was a couple of mm higher. I found out later that it does work but you really have to push to make sure it's seated all the way.

So take the cap off and look at the inside, maybe this is your problem. In my case the engine started but the distributor was making a gawd awful clattering noise.

Edit: I see from your post above that you've already checked that. Oh well, worth a try.

 

[NikiSpider]

I also forgot to mention that there was no spark but there is a steady 12 and ground going to the coil and thanks for the response, kcab. I checked the inside of the cap, no scoring or marks. Not even a mark on the contact point of the rotor to indicate it is functioning. Just a ticking noise and smoke.

 

[papajam]

Don't know if it will help in the diagnosis but I'm curious as to;
A) where exactly is the green wire attached and
B) what, if any, role the original coil negative to distributor black wire is playing.

 

[Alfajay]

I checked the Alfa wires running to the coil (green/black and solid green) and made sure they are connected correctly to the coil. Green/black is the positive showing 12 volts with a voltmeter.

I think Papajam is on the right track (usually a good assumption!). It sounds like you have the red/black wires from the electronic distributor wired correctly, but I am less certain about what you refer to as the "Alfa wires".

Does your wiring diagram support that the hot lead from the ignition switch to the coil should be the green/black? I'm not disagreeing, just don't have a '78 wiring diagram. Yes, I know your voltmeter shows +12 on that wire.

Typically there are only 3 wires connected to the coil in these electronic distributor applications (*): red from the distributor to coil "+", black from the distributor to coil "-", and some color wire from the car's ignition switch to coil "+". So the fourth wire you refer to, the solid green has me puzzled - where is that connected now? Where was it connected previously? What voltage does it read when it is disconnected from the coil with the ignition switch on?

(*) Unless the car has an electronic tachometer, which a '78 Alfa does not.

there was a clicking/ticking sound coming from distributor and it started smoking

You know, that's odd. It sounds as if you have TWO problems: a mechanical one causing the clicking/ticking, and an electrical one causing the smoke. Wires that are connected incorrectly can certainly cause smoke, but usually not clicking (unless it's a relay).

- Is it possible that your distributor is not fully seated, and you are hearing the drive cog clicking? Can you turn the rotor by hand?

- Once something electronic smokes, it is usually destroyed. Not to be pessimistic, but even if we figure out that the coil was mis-wired, and you correct the wiring, the electronic module still may not work.

 

[JoeCab]

Unless there is anything else I should check?

I forgot to add, the easiest way to check for a fried module is to smell it. There will be a distinct acrid smell that tells you right away the module has burned/shorted.

Jay's suggestion that the drive dog is not fully seated is a good one, too. Sometimes it can feel like it's fully seated and then jump 180 degrees when the car is cranked.

We can easily send you a replacement module, which is quite easy to install, or you can send in the distributor in and we can replace the module for you and re-test it for spark. Call on Monday and we'll get it set up.

 

[Geoman]

FWIW, I have the same setup. The solid green wire hooks up to the (+) coil terminal. The green/black stripped wire is not connected to anything, just tied out of the way.

 

[AlfistaChris]

If there are two wires at the + terminal of the coil ,one wire is usually coming from a condenser. It is for noise repression that may enter the cars positive supply and cause radio interference.
Not to be confused with the condenser at the distributor contacts that is vital part of the ignition system.

 

[NikiSpider]

Thanks for everyone's timely responses, you have all been such a great help. The module is def fried and the folks at centerline were nice enough to send me a new one along with a coil.

As it stands now I have checked the green wire from the ignition to the coil for continuity and it checks out; however, I am getting no voltage with the key on or when it is cranking. The green wire is plugged into the #16 terminal at the ignition and at the positive terminal of the coil. Checked coil for spark, no spark. I'm going to be working on this today and checking here to see if anyone has any ideas. At this point, I just need to know if the green wire should have constant 12? If so, can't I just plug the green/black wire since that is a constant when I turn the ignition on? AND is the green wire supposed to be plugged into the #16 terminal at the ignition?

Papajam, would you be able to list the terminal #'s and the wire colors for the ignition? The numbers cannot be read on your diagram even with a magnifying glass but they look like green 16, black 50, red 30 and brown I can't read for the life of me. I also have a yellow wire back there that is stock but not listed in your diagram.

Thanks Again,

George

 

[NikiSpider]

Also, the green/black and green have continuity when the key is turned to actually start the car, not when the key is just turn to prepare for start.

 

[papajam]

From the factory, the green wire is the ballast resistor bypass circuit. It provides battery voltage directly to the ignition coil positive terminal ONLY when the key is in the start position.
With the key in the on (or run) position, the coil positive is powered thru the ballast resistor via the green/black wire.

 

[NikiSpider]

So just the green wire should be used for the coil as Geoman said? How does the car keep running if the green wire is just for starting?

 

[Alfajay]

From the factory, the green wire is the ballast resistor bypass circuit. It provides battery voltage directly to the ignition coil positive terminal ONLY when the key is in the start position.
With the key in the on (or run) position, the coil positive is powered thru the ballast resistor via the green/black wire.

But aren't Bosch blue coils designed to be used without a ballast resistor? Would running one of these coils with a resistor damage the electronic module? I wouldn't think so, since it would be switching less current - not more. The coil might not spark, but I wouldn't expect smoke.

So just the green wire should be used for the coil as Geoman said? How does the car keep running if the green wire is just for starting?

When cars are wired the way that Papajam describes above, the coil is powered directly by the battery while the starter is energized, and powered through the ignition resistor when the ignition switch is in the "run" position. So there are two wires connected to the coil "+" terminal - one from the resistor, and one from the starter solenoid (how the wires are actually routed is an unknown to me). Again, when using a Bosch blue coil, the resistor is not needed, so that wiring could be simplified. Geoman: Do you have a blue coil? Might that be why one of your wires is tied out of the way?

 

[alfasrule]

Bet you wished you just kept those old fashioned POINTS in that car. Don't understand why you Alfa owners think your gaining anything by changing something that works just fine and is reliable. $10.00 and 30 minutes and you're all tuned up. Why waste the money?

I own a 75 Afetta Race car with POINTS and a boat load of trophies that came with the car proves to me there is no benefit by changing what the Alfa Engineers put in the car originally. I also own 3 other Alfas with POINTS and they all run great.

 

[alfaparticle]

Alfa Romeo stopped using points ignitions 30 years ago. They are not stuck in the past.

 

[Geoman]

Geoman: Do you have a blue coil? Might that be why one of your wires is tied out of the way?

Yup. I have the blue coil. IIRC, it was the folks at Centerline that suggested leaving off the green/black wire.

 

[NikiSpider]

I also have the blue coil, Alfajay and I have set it up as Geoman has suggested. We will see if this new electric module will start this baby up tomorrow! And thanks again everyone for the timely responses and excellent, knowledgeable advice.

 

[kcabpilot]

Bet you wished you just kept those old fashioned POINTS in that car. Don't understand why you Alfa owners think your gaining anything by changing something that works just fine and is reliable. $10.00 and 30 minutes and you're all tuned up. Why waste the money?

I agree with you. There's nothing wrong with the electronic replacements but, unless your original Marelli distributor is completely worn out or broken there is no need to replace it. I purchased an ID405 when I was restoring my Spider but I had some problems with it and I just didn't like the way it acted, the advance curve wasn't right in my opinion. So I removed it and re installed the original single point Marelli. I later found out that one of the springs was missing from the advance weights but I never fixed it or put it back in and sold it to a local guy for $150.

The original Marelli is much smoother and there is no truth to the notion that an electronic trigger is somehow going to give you a "hotter" spark and increased power. If the original setup was in need of a "hotter" spark why would it have come with a ballast resistor?

Which, BTW for the OP, is why you have two wires going to the coil from the ignition. One was for starting, which bypassed the ballast resistor and the other was for run, which utilized the ballast resistor. In your case, with the blue Bosch coil, you don't use a ballast resistor so the start wire can either be eliminated or just hooked up along with the run wire.