MG Car Repair: 1968 MG, alternator problem, wd 40

Question
QUESTION: My dad has a 1968 MG that's been sitting for a couple of years.  After cgarging the battery, I was able to get it started but after a while, it just dies.  Is it the alternator not charging the battery or is something else wrong?

ANSWER: Hi Chris, It takes very little current to run the ignition system after it starts. Try spraying something like WD-40 in the intake when it tries to die to see if you can keep it going. Any car after sitting for a couple of years will need the whole fuel system cleaned out to run.
Connect up a timing light to a plug wire and set the idle at a fast idle and watch the flash of the timing light to see if the flash quits first before the engine stops rotating or the light flashes all the way to the last revolution. That will tell you if the ignition is firing ok or if it is fuel that has stopped it.
Howard

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QUESTION: Thanks Howard I will try that.  This morning I was able to once again start the car and it runs as long as I keep the charger on.  It sounds like the alternator might not be charging. My next step is to take to an electrical place because I think it's the alternator not charging.  Any other info you provide would ne appreciated.

Answer
Charge the battery and remove the charger and start the car on the battery. Don't condemn the alternator until you have a good charged battery in the car. Then put a volt meter across the posts of the battery and read battery voltage and start the car. The voltage should not drop below 9v while the starter is engaged. Once the engine starts read the volt meter while at a fast idle. It should read 13.8v to 14.5v. If it does then the alternator is OK if the reading is lower than 13.8 you have an alternator problem.
Howard