MG Car Repair: Car kills after first start, fuel pressure gauge, wd 40

Question
After my 1972 midget has been sitting for a few days it is hard to start and after it starts the car will kill going down the road after about a mile and won't restart.  If I let it sit for five or ten minutes it will start and run great.

Answer
Hi Mike,
Your symptoms narrow the problem down to about a thousand things so you need to run tests to narrow it further.
All engines only need 3 items to run, compression, fire and fuel with conditions on each.

Compression will not go and come. If compression goes away, it will not return.

Fire and Fuel can do that so you need to isolate which is missing when it will not start.
To check fire (when it won't start) you can do a simple preliminary test by just removing a spark plug and attach the wire to the plug and lay the plug on a metal part of the engine and spin the starter and watch the plug. You should see a thick blue spark.

To check fuel you need to purchase a spray can of starter fluid or you can use WD-40 and spray it into the intake while someone tries to start the engine. (as before this must be done when it will not start)

If the engine does not stay dead long enough to run the tests, you will need to put a fuel pressure gauge in a "T" just before the carburetors and run a long hose out from under the hood and put the gauge under a wiper arm so you can see it while driving. Also put a timing light on the coil wire and run the timing light out from under the hood and put it under the other wiper arm with the trigger taped down so you can monitor the flash. When the car dies you can then see if you have lost fuel supply or spark at the time of failure.

Howard