Car wont start, no spark

[jrrbritt]

Hi all, hoping for some guidance. Starting my 57 t-bird (312 engine) for the first time in several years. I have changed all the fluids, carb is nice and clean, still the old battery but it has been charged and is enough to turn the engine. However it will not start, not even a catch or jump while turning.
So I got the tech manual and did the ignition system checks. Voltage drop to the resistor/ballast is in spec, though the wires are a little cracked the readings dont change when I flex them. resistance across the coil is good, so is the resistance through the main HT lead.
The only thing not in spec is the ballast/resistor. It was measuring too high with the OHM meter, so I cleaned it. Now it measures too low a resistance. Its off by .5 OHM, should be 1.3-1.4 and its .9 now. Is that enough to result in NO spark? It seems like I should be getting something. But I get no spark with the HT wire held next to ground, and nothing on the voltmeter at the end of the wire.
I can replace the resistor, but since its a special order part, I was wondering if there is anything else I should look at? Also, I noticed that the voltage at the ballast is 12 volts with the key in the "on" position, but it drops to 6 volts when I crank the engine. Is that normal?
Help is appreciated! Thanks.

 

[gbhrps]

jrrbritt,
You aren't getting any responses because there isn't a lot of activity on this forum, and because those who have read your posting don't have the answer you require. And I am one of them.

My best advice is for you to contact a local antique car club and ask some of their members to point you to a mechanic they recommend, someone who is familiar with these 50 year old electrical systems. A short chat with the right mechanic should be able to point you towards your fix. Good Luck!

 

[jrrbritt]

Thanks for that, I kind of figured that was what was going on. Good news is I sorted it out myself. Car runs now. Thanks though!

 

[Charley Beckman]

Car runs now. Thanks though!

Hi JR, glad to hear you got the problem solved. If you don't mind, it would be nice if you could post the solution, in case others can use the info.

 

[jrrbritt]

Turned out to be a combination of things. Isnt it always? Replaced the ballast on the coil, that was one issue. Still not starting, so I replaced the points with an ignitor. I have never learned points tuning, and I had an ignitor on my MG Midget that worked well. That did the trick. I suspect my problem was mostly related to bad points on the dizzy.

Now I just have to solve the overheating issue.....
Cheers! :cheers

 

[gbhrps]

jrrbritt,
Are you certain that it is overheating? My 55 Bird's temp gauge was telling me the same thing. It wasn't until I put in a secondary temp gauge (a prewired digital unit that sits just inside the top rad hose on the radiator inlet and has its leads run to the inside of the car on top of the tranny hump) that I discovered that the car rarely ran over 178 degrees F, even though the dash gauge was dangerously close to going off the gauge at times. I 've relaxed a great deal since then, but still keep an eye on it frequently.

Previously I did have an overheating problem back 10 years ago. The problem I found was that the heat riser ( the flapper valve at the end of the passenger side exhaust manifold before the exhaust pipe) was sticking closed, instead of opening up when the engine got up to temperature. Some people have stripped the flapper valve off the shaft, in order to stay stock looking. Others have just maintained a frequent watch on the heat riser to ensure it never sticks closed, and lubed it frequently with a spray on graphite lube.

There are other reasons for the symptom, such as the timing being off, the rad being partially plugged, the system needing a flush, etc., and some research into your particular situation needs to be done. Get back to us with more if necessary.

 

[57MexicanTBird]

I had a similar issue with my 57, the temp gauge was continuously in the red. The mechanic told me it needed a resistor in the wiring and that would bring the reading down into the correct range. After he installed the resistor it looked real good, but being in Arizona I was concerned that something might not be totally right. I bought an aftermarket gauge set and installed the Oil Pressure/Temp Guage combo. The new gauge is now confirming the water temp and they are both reading just at the 180 degree point. Even when the temp here has been well into the triple digits I am running at 180. Feel much better about it now.

 

[kevinrcase]

my gauge also near pegs the temperature chart but the surface temperature on the steel at the thermostat runs 90 to 100 degrees above ambient after running a while. It would be easy to put in a resistor in line if I knew what size.

 

[gregoryk7]

How did you figure it out?