Small plug in top of ignition coil important? - Alfa Romeo Bulletin Board & Forums

 1Likes
  • 1 Post By spiderserie4
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 04-17-2017, 07:43 AM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Small plug in top of ignition coil important?

In ham radio we have a saying akin to "don't let the smoke out of your transmitter, or it won't work--it needs the smoke to run."

I'm looking at P. 39 of the Spider 2.0 1985 Engine Maintenance Manual and it says check the top of the ignition coil to see if the 'plug is in position and the mastic filler has not leaked out."

Well there is a little opening a the top of the coil between the wire connections and indeed it appears to be empty and there is no mastic in there.

But then it says "if plug is missing or mastic has leaked, REPLACE IGNITION ECU AND COIL" (Caps mine).

Now my problem is a common one, starts and runs ok when completely cold but does not start after running for say 10 minutes. But...replace ECU and coil? And what is this plug anyway?

Mike
MikeRutkaus is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 04-17-2017, 08:16 AM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 5,251
I read that somewhere on a Bosch bulletin.

never seen one missing, but it seems to be a sealed expansion cap, whereby when a coil has failed real bad, the stuff (oil?) inside expands and leaks out there.

As for 'change the ECU', wouldn't bother about that to be honest, just now
The car starts and runs cold so the ECU is doing something right!


Coils normally fail when hot, so that might be the reason it doesn't start hot.
Get a new coil and go from there.
Attached Images
 
alfabeach likes this.

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.
spiderserie4 is online now  
post #3 of 11 (permalink) Old 04-17-2017, 08:19 AM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Hmmm I think I will order a coil from somewhere.

Thank you very much, I summarize your advice as: Coil oil boil.

Mike
MikeRutkaus is offline  
 
post #4 of 11 (permalink) Old 04-21-2017, 10:41 AM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Hi, got a new sort of generic coil (listed for this '85 Graduate) but when took off original and cleaned it, noticed the 'plug' was really still there. Installed new coil anyway, no change in symptoms which currently are:

1. Starts instantly and runs well when completely cold.
2. When I stop and start it say after running 5 minutes, it restarts fine, maybe even ten minutes restarts fine, but when temp needle gets up near middle to full operating temperature, and I stop and try to restart it, it does not restart, and THERE IS NO SPARK (as shown by neon bulb in series with plug wire.

Any ideas appreciated. Have had car for ten years or so and followed l jetronic checking instructions and checked or replaced practically everything mentioned in the l jetronic procedures.

Any ideas appreciated,

Thanks,

Mike

1985 Graduate
MikeRutkaus is offline  
post #5 of 11 (permalink) Old 04-21-2017, 10:56 AM
Senior Member
Gold Subscriber
 
rogerspeed's Avatar
 
Join Date: May 2005
Location: OC CA USA
Posts: 3,323
Have you tried to restart when hot with the throttle fully depressed to the floor/

current:
83 Spider Veloce
ex:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

solve problems, learn something new!
rogerspeed is offline  
post #6 of 11 (permalink) Old 04-21-2017, 11:17 AM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 9,741
I suggest that you connect a plug wire directly to the coil and check for sparks when the engine is hot. If you get sparks this way but not from the plug wires connected normally then you have a problem in the distributor cap and/or rotor. The coil is fired from pin 1 of the ignition ecu so check that connection. If you can borrow an oscilloscope you should see pulses of at least 250 volts at the coil primary when the coil is supposed to be firing.
It is possible that one of the two crank sensors is failing when it gets hot. Each one should read 800 - 1200 ohms. The ignition computer also gets inputs from the vacuum sensor, ignition temperature sensor and throttle switch but I don't know if a failure of one of these would cause a complete loss of spark.

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
post #7 of 11 (permalink) Old 04-21-2017, 11:42 AM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Yes, tried many times to restart when hot with throttle pedal in all positions.
Thanks
Mike

1985 Graduate
MikeRutkaus is offline  
post #8 of 11 (permalink) Old 04-21-2017, 01:07 PM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 5,251
its a strange one.

so car runs perfectly fine when driving along (engine hot) - so in fact you could happily drive all day long (Spark and fuel fine), right?

yet there is definitely NO SPARK when you turn it off (engine hot) and try to restart......?

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.
spiderserie4 is online now  
post #9 of 11 (permalink) Old 04-21-2017, 01:35 PM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Thanks Ed, I did try the coil direct to plug with the neon bulb in between, nothing when engine wouldn't start. Distributer cap is new and rotor looks fine after I polished it. I'm assuming for now something is telling the ignition ECU not to make a spark, or something is wrong inside the ECU.

Next will check the position sensors near the clutch, which I'm pretty sure I did some years ago, but...

Mike

1985 Graduate
MikeRutkaus is offline  
post #10 of 11 (permalink) Old 04-21-2017, 01:51 PM Thread Starter
Registered User
 
Join Date: Apr 2017
Posts: 6
Hi, yes there is a good possibility I could drive a long distance if I didn't turn it off, but I wouldn't try it, ha ha. Drove it about 12 miles a couple weeks ago when I thought it was working, but it did die after I made a quick left turn then I coasted to a safe spot and it wouldn't start. I called my friend the tow truck driver but I got it started before he arrived. I offerred him $30 just to follow me the 4 miles to home. I almost made it, it died again about a mile from home. So it will run a long time with no problems, and I've fixed several possible vacuum leaks since then.

Yes definitely NO SPARK at the times it doesn't start when hot. I put a little neon bulb thing in the plug lead and it definitely flashes when there is a spark.

In the spirit of eliminating possibilities, I tried to start it hot an hour or so ago, while I was sucking very hard on a tube I connected to the vacuum sensor next to the ignition ECU--nothing.

I can't imagine the position sensors near the clutch getting hot and not working but anything's possible. I'll check those again. And just to triple check I will look at the coil primary voltage when cranking and not starting.

Thanks,

Mike

1985 Graduate
MikeRutkaus is offline  
post #11 of 11 (permalink) Old 04-21-2017, 02:26 PM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 9,741
Try touching the neon to the primary terminals of the coil when the car is running and see if it flashes. If it does then you can use it to test for a pulse when the engine will not run

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
Replace with
For the best viewing experience please update your browser to Google Chrome