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Electronic Distributor changeover - Smoking distributor, not starting.

12K views 36 replies 14 participants last post by  JoeCab  
#1 ·
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
 
#2 ·
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.
 
#3 ·
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
 
#8 ·
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.
 
#4 · (Edited)
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.
 
#5 ·
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. :confused:
 
#6 ·
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.
 
#7 · (Edited)
NikiSpider said:
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.
 
#10 ·
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.
 
#11 · (Edited)
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
 
#13 ·
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.
 
#15 · (Edited)
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.

NikiSpider said:
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?
 
#16 ·
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.
 
#20 ·
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.
 
#21 ·
Yeah, and similarly Alfa wasn't stuck in the past when they ditched carbies and went with EFI. But some of us (no names please) still insist on old school, right Ed? :p

Sorry, couldn't resist.:D
 
#19 ·
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. :p
 
#23 ·
Hello All :)

I connected green wire and it was trying to start. Did some voltmeter testing and the green wire only gets juice while the car is cranking. So I disconnected the green wire and connected the green/black wire and now the car is running and revving beautifully. Thanks again for all your help!!!

Evviva,

George
 
#27 ·
George, as I said in an earlier post: the green wire is for "start" and was originally hooked directly to the coil. The green and black is for "run" and was originally hooked to the external ballast resistor and then to the coil. In your case you can just hook both to the coil (won't harm anything) that way you don't have to worry about the live end of the green hanging out there with 12 volts on it when you're cranking. Or, you could put tape over it but best way is to just leave it connected.
 
#24 ·
I hope NikiSpider solves his problem. Sorry to change the issue here NikiSpider. Just pointing out the fact that Alfas just run fine with this 30 year old technology. I have Marelli single and dual point systems as well as 1 Bosch system. I want to make those Alfa owners out there know that the systems in place in their cars are adequate and very reliable!

Alfa was forced to change these systems because of emission requirements, not because they wanted to.

A simple relay(points) with high voltage coil is all you need to run a motor. No transistors, ECU's or Engine Management Systems. One wire instead of Hundreds in some cases, all for what 3 to 5 more miles per gallon, it ain't worth it to me.
 
#30 ·
LOL, you guys are great. Thanks for the grin!

Just FYI, though. The Centerline ID405 is EMP-proof (perhaps an added selling point for the website, Joe? :p) Just a diode and a resistor in there, Boys!
 
#32 ·
This is the 21st century and you guys are still worried about the Russkies attacking? :D

Alfa switched for the same reason everyone switched: electronic ignition doesn't need adjustment or maintenance, gives more precise control of spark timing with more customizable maps for better driveability, and greatly simplifies the design of the distributor (and ultimately lets you get to distributorless ignition). Yes, it can fail, but overall those failures are rare enough that compared to regularly adjusting/replacing points it's a less maintenance-intensive system.

I've only had one electronic ignition system go bad myself (a Bosch module in the wife's Audi) and even that was limp-home-able. Even the Lucas (may they be cursed by the gods!) electronic ignition on my TR7 was still working well after thirty years with zero maintenance.

Theoretically, electronic ignition can also increase spark energy by providing a faster, cleaner break than physical points. I won't argue this one way or another beyond to say that the Giuila has electronic ignition an it's never, ever had any problems with not getting a good spark due to fouled plugs or whatever.
 
#33 ·
Or a Timing Light. Well I've been setting these things for so long I only use these tools to validate my settings. Anyway that's what forums are all about. I enjoy these discussions and never get upset about the individual on the other side of the keyboard. He's entitled to his opinion just like everyone else on this site. Just stating my feelings.
Owning Alfas for over 25 years as well as being an electrical engineer for over 30 years I just want to set it straight. Hope I don't offend anyone. Just having a blast!!
 
#34 ·
Personally I'm not arguing against the advantages of electronic ignition - I'm just saying that there is no good reason to tear out a perfectly good points distributor to replace it with an electronic one. Bang for buck is just not there. If you need to replace the original because it's worn out or otherwise broken then, by all means, go with an electronic replacement.

Changing points on the Alfa is not a big deal - you pull the distributor and take it to the bench where you can clean it up, lube it, check the advance weights and install the new points, condenser and rotor. I also replace the cap and have no problem getting 15-20k between servicing's but if the old Marelli ever goes south, yes I will replace it with a 123 or other aftermarket electronic distributor. With regular service and light lube of the advance weights and bushings the distributor will last an awful long time though - I don't see it ever really needing to be replaced.
 
#35 · (Edited)
She's running great! Maybe the points or condensers were shot but there is a significant improvement in the way she revs, drives and the exhaust even sounds better. She's timed perfectly. F at idle and M at 5k. No ping, only rpm! I am still keeping the old distributor setup for storage but, either way...Goodbye, Marelli and Hello, Bosch! :p

Special thanks to Joe at Centerline for taking care of me and sending a replacement module and being so helpful over the phone.

Love this place and all of you guys are great!!! Thanks to everyone who helped me through this!

MIGHT advance it just a hair and throw some octane boost in there but for now I'll just enjoy a short independence day drive before I head out for the festivities. > : )

Happy 4th and God Bless America!

-George
 
#37 ·
She's running great! Maybe the points or condensers were shot but there is a significant improvement in the way she revs, drives and the exhaust even sounds better. She's timed perfectly. F at idle and M at 5k. No ping, only rpm! I am still keeping the old distributor setup for storage but, either way...Goodbye, Marelli and Hello, Bosch! :p

Special thanks to Joe at Centerline for taking care of me and sending a replacement module and being so helpful over the phone.

Love this place and all of you guys are great!!! Thanks to everyone who helped me through this!
George - glad to hear you persevered and there is a happy ending!