Have an 84 Ford Bronco with 351 in it. Going down road and it simply stops like you turned off key. Sometimes it starts right up, other times it will not. I thought it might be bad connections on coil. Anyone else have ideas?

 

99.9% sure: The (Ignition Module Box).
Normallylocated in engine compartment on the driver-side fender-well.

 

Ignition boxes NEVER go bad - like some people think. Unless it melted down (and I've even seen them run then). Try dirty battery cables or bad ignition lead wire (or connector) to solenoid.

 

It is basic knowlege that "ANYTHING" electrical will fail sooner or later.
With this type of Ford Ignition system, there is a history of the Modules going bad. When they start going bad, they always show the early signs such as this person is having with his 84 Bronco.
The problem is that one of the modules inner chips is over-heating at times, and this causes the ignition-module to completely shut down. Once the chip has cooled down some, the car will start and run again (unless/until the chip over heat again). After a while, the chip will finally burn-out completely and the car will not start because the Module is no longer fuctioning.....Bottom-Line: A New Ignition-Module Must Be Installed.

 

Guess again! That's called the lazy computer guys explanation. It's hellish far-fetched and a last ditch effort to cover up the fact that they don't know WHAT THE HE** THEY'RE TALKING ABOUT. Like you said all electrical systems fail - USUALLY ALWAYS the UNCOVERED parts (like wires).

 

And - by the way- they have the exact same symptoms.

 

Yes, as yousaid, aloose wire connection could also cause such a problem (I never said that it couldn't be a possible cause). In fact, I stated that I was 99.9% sure...not 100%.
When I post anything on this Forum, its a result of 35 yearsof being aASE certified mechanic; and even with that, I don't claim to know everything all the time.....thus I'm no shade-tree mechanic.
This Ford Forum is open to the public...thus it doesn't belong to any one person to master over it (as I have notice youhave beenclearly attempting to do).
You seem to have a habit of stepping-on anything that I may post on this Forum in my attempts in helping someone...I DON'T GET IT! My bet is that you don't get the respect you wish for where ever you live or work....so you attempt to get it from this Ford Forum.....SO SO SAD.
If you don't agree with something someone has posted, just post your suggestion to the matter at hand and leave it at that.....there is no need for you nor anybody to slam another persons suggestions.
Personally, I don't know EVERYTHING, and I don't try passing myself off as someone who does.
As for me, I will continue as I have in my attempts in helping someone when I can on the Forum....no matter what some problem person may come calling with.....Have A Blessed Day!

 

What are you? A liar hiding behind God? You DO claim to know everything. I just attempt to help most times - but on this I am quite sure. Does your certification make YOU an electronics technician? Have you any insight into circuits and faults? Do you Know anything about how to make a computer chip? Or are are you crying for giving up half way? I have over 30 years of REAL experience and I'm not right on all the time. I mustn't be as perfect as you claim to be but 99.0%self-indulged is what you are. I've actually worked in transmission shops too- How about you sad jerk. You just are like any big talker I ever met. Looking to sap people's pockets at their expense while feeding your ego. I'd say only an idiot wouldn't check wires and connectors first. That'd be you from what you say. Only you downplay the basics to make a point on something that may temporarily work and not be the problem at all. I need no respect. I hatemost people because all humans (including me) are born partly evil. Some act on it as antagonists - that would be you. I'll come back at a lazy explanation when and how I see fit when it's wrong! I got an idea - go get an electronics degree and then after a few years when you are somebody talk to me. Else try bothering a know-nothing.

 

Guess I'll pop in my 2 cents worth. Different vehicle but same symptoms. While serving the US Army in Germany dual duty as an Electronic Warfare Interception Systems Repairer and as Motor Sergeant, we would have this issue on the Dodge pick-ups during field excecises. Problem was 99.9% of the time a grounding issue with the Ignition Module as the hold down screw/hole would rust up enough for the unit toend up with a flakey ground. It would come and go as the truck was bounced about. We would just drill a new hole and instead of using a screw like the factory, we would bolt the unit down with a helping of dielectrical grease and star washers on both sides. Good luck and let us know how you make out.