Extreme hot coil, no spark when hot

[4yuckfous]

Hello together
It's a time ago, when I wrote about the hot engine and no running problems.
First I was thinking about boiling gaz in the carb or fuel lines, so I insulated the fuel lines and mill a synthetic plate between the carb and the intake.
The temperature under the shaker is always so hot, that this issue was my first idea with the boiling gas.

Last week I was in my friends shop to renew something and whe figured out that the coil was extremely hot without running the engine.
The weather is verry nice and hot, so after starts the engine and a short drive from a few meters the engine dies.
After push the car back in the shop we tested the spark and there was nothing.
The coil verry hot and round about 5.4 Volts on the coil.

Measures:
Changing the FBO ECU with the original one
Changing the Accel coil with one from FBO
Fix the ECU and alternator regulator with Tubtara on the firewall to have good ground
Results:
No spark

Measures:
Changing the FBO coil back with the Accel
Result:
Spark and run

So yesterday I was driving around and what happened.....?
Engine hot...... no spark.......

Now I need realy help from you enthusiasts.
Thank you in advance
Andrea

Here my present setup:
Distributor: Mancini MRE-6990
Coil: Accel 8140C mounted horizontally on top of the engine
Balast Resistor: 2-Pin
ECU: Mopar original (before FBO)

[dodj]

To start, how many pins on your original mopar ecu? 4, or 5? If it is a five pin ECU and you have a two pin ballast, there may be some funny wiring going on around the ballast.

[4yuckfous]

Just mede som pics.
It's a 5 pin ECU
The diagram shows how I have connected the ignition

[dodj]

Can you describe the operation of the starter relay you have drawn? It has one more connection than the usual mopar relay.
If it is as I suspect, the wire going to the + side of the coil has 12vdc all the time which will overheat your coil and burn it up.

[4yuckfous]

The + that goes from the reley over the resistor to the coil is a ignition +.
Only powered when the key is on ignition position or starting position.

I have messured the ampere from the battery if the key is on off position
and there I have a 0.00 consumption.  No power consumtion or issue.

So far as I know, it's a original starter relay.

[dodj]

I was a little confused as it looked like there were five terminals on the relay.
The wire that goes to the coil + from the relay  has 12vdc all the time. It will fry your coil in a relatively short period of time. The coil should be getting reduced voltage after start-up. So after the engine starts, the coil + supply should be going through the ballast resistor.

Also, your ecu is meant for a dual resistor. I'm not really sure how a five pin ecu behaves when wired as a four pin. Never done it or tested that kind of connection.

[Kevin71]

I had  a harley years ago that would run great for awhile then would just shut off for no reason.  I would let set for a hour and it would crank right back up and run for awhile then shut off again.  Had several shops look at and of course it didn't it there.  Finally I come by the harley shop one day just as it shut off.  Pushed in and the mechanic looked at it discovered it was the coil.  When it heated up the wires expanded and lost contact shutting it off. When it was cold they touched and it ran.   Couldn't believe it.  But a new coil fixed for good.  Happy trails after that.

[4yuckfous]

@dodj
Do you have a correct diagram, how do you think that it works well?

[AussieMark]

I had  a harley years ago that would run great for awhile then would just shut off for no reason.  I would let set for a hour and it would crank right back up and run for awhile then shut off again.  Had several shops look at and of course it didn't it there.  Finally I come by the harley shop one day just as it shut off.  Pushed in and the mechanic looked at it discovered it was the coil.  When it heated up the wires expanded and lost contact shutting it off. When it was cold they touched and it ran.   Couldn't believe it.  But a new coil fixed for good.  Happy trails after that.

Try a known good coil and see if it cures the problem.

[4yuckfous]

I tried it with a new (in stock) FBO Coil and a old in use coil.
Same result no firing.....  see measure in the initial post


Is there any known issue with the position from a Accell Coil?
Horizontal or vertical mount......?

Witch ECU and Coil combo is recommended?

I/we have really been 

[RCCDrew]

With the FBO is the red light blinking when cranking? My FBO is brand new and having this same problem.  I'm thinking that the FBO can't read the distributor.

Edit: diagnosed mine to a bad new module.

[Fern]

I installed the FBO unit and remember it stating that you must use there coil.  Prolonged use of another coil would damage the unit.

[dodj]

@dodj
Do you have a correct diagram, how do you think that it works well?

You really only need to take the wire that goes to your (+)coil off the starter solenoid where it is getting 12v all the time in start and run and move it to the wire that comes off your start switch. This wire only has 12v when your key is in start. That is the only time you want the increased voltage applied to your coil. Then when you release the key, your coil will get it's + feed from the ignition switch through the ballast resistor.
You should have a 4 pin ecu with a single ballast resistor. 

[Falbz]

Make sure the blue wire you spliced into the ballast resistor is connected good and providing a good power to ECU.  My buddy had a similar issue where the car would not get a spark and there was a weak connection at the ballast resistor wiring.  I soldered the connection for him and the car has had no more spark issues.  Good luck

[4yuckfous]

Hello everybody

Have received a new ECU today from FBO including the coil.
They don't need the balast resistor, the "Bridge" is also included.

Will try asap.....