1981 no spark.

autox19

True Classic
So once i got the miss figured out (new coil, module, fuel filter and injectors) it ran fine...... for 2 days. Then it wouldnt start. No spark. No spark from the coil as well. 8.5 v. To from the +side of the brand new (one of our vendors) coil and module.

What next?

Odie
 

kmead

Old enough to know better
By module do you mean ignition module or the sensor in the distributor?

The GM ignition module could have burnt, particularly if the previous owner replaced it without putting the heat transfer paste between it and the aluminum heat sink.

The sensor and associated wire in the distributor are well known weak points, it would be the most likely candidate. Many owners carry a spare.
 

lookforjoe

True Classic
For an electronic ignition, that seems to be too low a voltage. My old Volvo setup wouldn't run if the volts dropped under 10 to the coil. I had to run a separate swtiched supply (kinda like the starter relay) to get system voltage to the coil.

Got any pics of the setup and how it's main input (+, -) are wired ?
 

autox19

True Classic
Module. The one under the heat sink (that i used the electric goo,forgot the name) on. Is there a way to test the pickup?

Yes i have a pic. I found a few threads that said they had low voltage as long as the brown wire was pugged in. They unplugged the brown and it went to 12. None had a resolution i could find


Odie
20200725_210525.jpg
 

autox19

True Classic
Ohms check.
1.5 at the 600k setting between the + and -
14 at the 60k setting between the - and the coil out to the dizzy ( might be .14 i cant read my own writing)
.73 at the 6k setting between the 2 pins that connect to the module (from the pick up)

Odie
 
If your coil has an external ballast resistor, you would not expect the full battery voltage across it when it is turned on. The 8.5V may not be far off.
 

lookforjoe

True Classic
What are all the additional wires on the coil for? Do you have a schematic (for the newer added parts)? Since it ran before, it seems most likely a component failure if you have + & -
 

autox19

True Classic
Ok here we go.
+. Pink comes from ignition. Red to/from module. Black to capacitor.
- brown to tach. Black to/from module. Big black actually has black and yellow for fuel injection signal.

Odie
 

kmead

Old enough to know better
I am away from home and my manuals along with Brad Artique’s Spider book or I would look this up for you.

I did find the following over at Mira in the 124 Spider Electrical Trouble Shooting Manual:

3D2146B7-EE71-46B4-91A5-A4EBCD5735B6.jpeg

635B9B6B-8E33-457A-8318-7FBBA8671252.jpeg

617A4D8E-C557-44C2-A240-EAF20981C1EB.jpeg
 

lookforjoe

True Classic
Ohms check.
1.5 at the 600k setting between the + and -
14 at the 60k setting between the - and the coil out to the dizzy ( might be .14 i cant read my own writing)
.73 at the 6k setting between the 2 pins that connect to the module (from the pick up)

Odie
1.5ohms seems within spec for the primary winding of a coil of this generation.
14K ohms is very high for secondary winding - 6-10KOhms would be normal for this type of coil. Do you have another coil you can swap in to try? Any coil intended for electronic ignition from the 80's-90's should do, really
 

lookforjoe

True Classic
Ok here we go.
+. Pink comes from ignition. Red to/from module. Black to capacitor.
- brown to tach. Black to/from module. Big black actually has black and yellow for fuel injection signal.

Odie
Why does it need a capacitor? Is that for Radio suppression? Maybe remove it?

I would still try connecting a coil feed (instead of existing pink) that has battery voltage with key on & see if that makes a difference. There is no ballast in the diagrams Karl posted, so no reason you should have such low input voltage.
 

autox19

True Classic
yes it is for radio suppression (which I dont have a radio for it so I will removing it )
I will look to see about another coil, I might have the mallory coil that the PO had on there still around.
Will try running a clean 12v to the coil as well.

Odie
 

autox19

True Classic
good news bad news. I know the symptom of 8.5v IS the issue. I jumpered 12v from the battery and it started right up. So the bad news is now I have to trace lines to find out why/where the voltage drops.

Odie
 

Rupunzell

Bernice Loui
Check the Ignition switch and all related to that set of wiring. Whole lotta current is run into and out of the ignition switch and they don't happily switch and pass that amount of current forever.

Bernice
 

autox19

True Classic
Check the Ignition switch and all related to that set of wiring. Whole lotta current is run into and out of the ignition switch and they don't happily switch and pass that amount of current forever.

Bernice
does the spider need the same brown wire mod? Or am I chasing a fix for a symptom rather than the real problem

Odie
 

lookforjoe

True Classic
I would just add a relay - the 8.5v would be enough to trigger a relay coil, I'd expect. Just add a fused feed off the battery or fusebox if they have one in the bay for 30 & 87 on the relay. Existing wire goes to 86, 85 goes to ground, done.
 

kmead

Old enough to know better
I would second the relay approach. Getting load off the ignition switch is always a good idea with any Fiat.

Starter relay is a definite 124 need. Unloading headlights, wipers and then general running off the switch would be good without question.

On a 124 most peoples power adds come off the alternator versus adding a brown wire. The starter being in the right spot is also a great gateway to power but it is somewhat hard to reach.
 

autox19

True Classic
Hooked up the relay. Started right. Up. Put it in reverse and it died. Started back up. But it in 1st and was fine put it back in reverse. Dead.. didnt let out the clutch. Just put it in. Looks like i am going to chase a possible short in the reverse lights

Odie
 
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