A continuation of my old post - I have a 65 coupe that has been giving me problems for the past three weeks.  Car will run for about twenty minutes and then shut off.  It is not a coolant issue, nor does it appear to be a fuel issue.  I have replaced the coil, resistor, ignition module, plugs and wires, starter and solenoid, and checked the timing and still have a problem.  (Thanks to Don for his help with my starter sticking problem). Next up for the troubleshooting is to replace the ignition switch and possibly the distributor.  Anybody have any ideas or suggestions?  I'd be glad to hear them.  Thanks.  

Hey 65mustang,

I'll admit right up front that I'll never be accused of being a good wrench. But owning a '65 coupe with a 200ci has helped me begin to understand what's going on under the hood.

Being more of computer guy, I'll throw this out. I've seen computers do the same thing. In the end, the problem seemed to be a bad contact on the logic board. After the computer heats up, the connection comes loose because of heat expansion.

Could this be happening somewhere in the ignition system? How long before the car will start again?  

gclark,

Sounds logical to me, but we haven't found any indication of a loose connection anywhere.  I am not an expert wrench yet either (except on a Honda), but am trying to learn.  Since my last post, we've replaced the ignition switch and tumbler, and now the car runs for about thirty minutes.  It takes about twenty to thirty minutes before the car starts again.  Our next course of action is to replace the distributor tomorrow.  I've had a few people tell me that could be the problem.  If you have any other suggestions, I'm all ears.  Thanks.  

Help!!! I've replaced the ignition switch and that didn't help out either.  Now I've pulled the distributor, but nobody seems to have a replacement that matches the part number printed on it (C9ZF12131A by Motorcraft).  I've checked at a Ford dealer and at all the parts stores including all the online Mustang sites.  I'm getting ready to just by a new Pertronix Ignitor II along with a new cap and rotor.  Anyone out there who believes that will work, or how I can find the correct replacement distributor?  Please help - Thanks.  

I would carefully check the grounds associated with the ignition circuits for good clean connections. When the engine has died, try hooking up a timing light to one of the spark plug wires and crank the engine and look to see if the timing light lights. if it does, then you have spark. Maybe check all other spark plug wires also with the timing light. If that checks out, try using some engine starter spray in the carb. then see if the engine starts. when the engine runs, is it running smooth? if not, check the timing.  

When it quits running is there still any spark at the spark plugs. With some insulated pliers, hold the spark plug wire boot with plug in it(use a spare plug or unscrew one) against the head and have someone turn over the motor to see if there is a spark. If you have a spark, it may be a dirty fuel system or fuel delivery problem. Look down the carb venturi and work the butterflies and see if gas is being squirted down the barrels. There is a screen in the fuel tank that will stop up with rust flakes after a few minutes of running then the engine will die. After sitting the rust will fall off, allowing flow once again until started and ran. You must have fuel, air, and spark.  

mach170 and cushman350,
Thanks for the info.  If the distributor change doesn't work, you have given me some troubleshooting tips I had not heard from anyone else.  Hopefully there is light at the end of the tunnel as I am anxious to get my car back on the road.  I'll keep you posted as to my progress.  Once again, thank you for your replies.  

mach170,
The engine is running smooth the entire time and then just shuts off.  It has stumped just about everyone I've talked to.  We've checked fuel flow and it appears to be working just fine.  The engine gets really hot, so that is why I've focused my efforts on the ignition system.  Thanks for your reply and please let me know if you think of anything else.  

To make things simple, remove the thermostat. start the engine and see if the overheating problem go away? does the engine run cooler? does the engine still die?  

How hot is the engine getting?  How long do you have to wait before it can be started and run again?  No one has mentioned vapor lock yet, and that can cause this type of problem.  If the fuel pump or fuel lines in the engine compartment get above 130 to 140 degrees F and stay there, that's enough to cause vapor lock.  You can tape a meat thermometer on the fuel pump and to other locations around the engine compartment (such as inlet to the carb, the fuel line between the fuel pump and the carb) to get an idea of how hot things are getting.  

mach170,
I had actually replaced the thermostat also about two weeks ago.  Replaced the distributor today and car is running just fine now.  The distributor cap appeared to be fine, so I think it was the internal components.  Whoever had changed the car from points to electronic ignition used a distributor from a 1979 Ford F150 Truck with a 302 engine.  I'm looking to get an MSD distributor and ignition module in the future to avoid this problem again.  At least I'll know what I'm looking for in the future.  Thanks for your help.  

bperkins,
Thanks for your reply.  It turned out to be the distributor as the car is running fine now.  Based on your post however, I do plan to reroute my fuel line so that it is not as close to the block as it currently is.  Hopefully I can avoid having a fuel/vapor lock problem in the future.  Thanks for the information.