Triumph Repair: Engine stops, fuel pressure gauge, bright sun light

Question
I own a 71 Triumph Spitire, and I would like to know what makes the engine stop when I'm at a stop light. This usually happens when I've driven the car for about an hour.
Thank you,
Luis Aguilar

Answer
Hi Luis,
Your symptom narrows the possible causes to about a thousand. You will need to run some tests to narrow it a little more.
All engines only require three things to run, Compression, fire and fuel with conditions on each. You can eliminate compression, as when compression goes away, it will not return. Fire and fuel can, so you need a method to see which went away at the time the engine stopped. First is the idle too low (below 800 RPM)at the time? Is the clutch dragging (hard to get into 1st or reverse) If they are ok you need to know if fuel or fire failed at the time. Will the engine start right back up? If all this is ok then you need to know which is lost. To do that you need to be able to "See" fire and fuel and to do that you need a timing light and a fuel pressure gauge and a extended hose and a fuel line "T".
These are not expensive and can be purchased at most any auto parts store and even at Wall Mart.
Put the "T" in the fuel line close to the carburetors and run the long hose out from under the hood and place the gauge under a wiper arm so you can see the fuel pressure when driving. Put hose clamps at each joint. Next, connect the timing light to the coil wire and run the wires out from under the hood and place the light under the other wiper arm and tape the trigger down and if you are testing in bright sun light, you may have to tape a piece of cardboard on the windshield over the end of the light so you can see the flash of the timing light when you drive.
When you stop at a light you need to monitor the two to see if you maintain a flash and fuel pressure on till the engine quits turning. If one of them stops before the engine quits spinning then that is the section you need to test, fuel or fire. Right now you have no idea which section is failing. Or you could do like some shops do and that is keep replacing parts until you get lucky and hit what is wrong. No one has a crystal ball to tell you what makes you engine die at lights, you or some one has to test to find it.
Howard