Ahhhgh!
Just found the gremlin!
The push- on positive connector to the coil has a broken connection inside the angled plug. Replaced it with a crimp on, and it starts fine. Fingers crossed!
Back in 1973 or so I received a new 1973 or so Mercury Capri (German built) with a v-6 in it. The car belonged to a family friend. The owner had been to several different dealerships, both Lincoln and Ford, and none of them were able to resolve the problem he was having. The symptom was the engine would die, just like turning off the ignition key. It would soon or immediately restart and run great until the next time it died, which could be within moments to hours, even days (several trips later). This was before the advent of electronic ignition, so it was a point and condenser based ignition system.
The reason I wound up with the Capri is because my father was boasting to his friends about how I was really good at finding unusual problems with cars, and he felt I could certainly find and solve it the issue with the Capri, despite the fact no other dealership had yet been able to figure out the problem. (thanks, dad! heh heh...). The owner told me to keep it for as long as I needed, and drive it as much as I had to, in my effort to fix the problem. He had filled the fuel tank, and told me to keep track of the gasoline I put into it so he could reimburse me. He also told me all of the items the dealerships had replaced already. Carburetor, fuel filter, fuel lines, points and condenser, ignition coil, distributor, ignition wires, fuel pump, fuel tank sending unit, fuel tank, spark plugs. Essentially the various technicians were throwing parts at the problem (under warranty), yet the problem persisted. At least I had an idea of what I would not need to replace from the list of items already replaced.
After a week of dinking with it, including taking it to my local college class I was taking and scoping the engine, and finding nothing, I decided one early Saturday morning to take it for a run on the Pacific Coast Highway (PCH, SoCal, Malibu area). Up to this point the Capri had been running perfectly, absolutely perfectly. Once I hit PCH, and noting there was very light traffic, I opened up the engine until I hit 118 MPH. Then I decided to cool my jets and used rolling resistance and downshifting (4 speed manual) to slow things down so I could turn around and go in the other direction. As I was putting in the clutch to downshoft I noted the tachometer was dropping to 0 RPM, but as soon as I let the clutch out it would begin to show me the engine RPM. I kept downshifting and saw the tach behave like that each time I engaged the clutch. I rolled into a turn-out on the side of the road, and the engine dutifully died when I put the clutch in as I came to a stop. I was finally able to duplicate the problem. With the teanny in neutral and clutch in I cranked the engine - no go. I let the clutch out and it fired up immediately.
Perplexed I got out of the car and popped the hood. As I was looking at "stuff" I took note the ignition coil's positive wire was resting on the clutch cable. Hmmm, and right next to the clutch cable where the wire was resting was a push-together connector for said wire. On a whim I fired up the engine, and while it was idling I reached over to the primary wire's connector the lightly touched it. The engine died. I stopped touching the connector and restarted the engine. I then touched the wire connector and again the engine died.
Well, it was clear to me there was an intermittent open circuit at the connector. So, having no tools with me, I disconnected the connector halves, and looked at how they were constructed. For the male connector there was a rubber hood that was holding a bared ignition wire against the head of a small carriage bolt. The female connector was made of another robber grommet that acted as an insulator for the female connecter, which I believe connected to its wire end with a crimp. In short, the positive connection between the bared wire and the carriage bolt head was only secured by the rubber insulator hood, and it was clearly inadequate. I was able to roll the two rubber pieces back along their wires, removed the carriage bolt, twisted the bolt head's bare wire to the female wire lead, then pushed the two rubber connector parts end together to provide insulation for the circuit. It was a simple, yet crude, field repair I hoped would work.
I started the engine, and now no matter how much I touched that wire the engine kept running. I was on top of the world. I rerouted the wire so it no longer laid on top of the clutch cable, as that was just more trouble waiting to happen (cable rubbing through the wire insulation in time). I went blasting up PCH in the return direction, got through Topanga Canyon inn record time, eventually rolled up to our house with a big shit-eating grin, and told my parents that I had found and repaired Dr. Lewis' problem with a temporary fix. I then explained what I did, excluding the part about going 118 MPH, and what I had done to fix the problem - temporarily, as I wanted to use a better connector. My parents could not have been happier for me, my father especially as I had come through for him after he went bragging about me to his fellow physicians as they were grumbling about how hard it was to find a good mechanic...
I had not considered going to the various dealerships and sharing what I found with the techs who had worked on the car. Years later I thought I should have done so just for them to know to look out for problems caused by such a cheap connector design. But, I didn't. Years later I began to work at the Ford dealership, and found they had Technical Service Bulletins (TSBs) that came out routinely to share finding by others. I realized I likely could have helped out others had I just said something to one or more of those technicians. I made up for that later with some TSB-worthy tips that made it out for others to read.
Anyway, that was my first significant repair I made after so many other technicians had not been able to find and repair a problem that really bothered the owner of a car. Over the years I would continue to correct things others had been unable to. I learned early on to be patient, listen to what an owner says re: what happens, when it happens, and under what circumstances. And I never forgot the bad connector design Ford had used. It sounds similar to the ignition coil connector causing the problem mentioned in this thread by
[B][I]1973 Mach-1[/I][/B] ( (an apparent stress fracture from being pushed on and pulled off over many years?)
From above:
Ahhhgh!
Just found the gremlin!
The push- on positive connector to the coil has a broken connection inside the angled plug. Replaced it with a crimp on, and it starts fine. Fingers crossed!
