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A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Ford
Satisfied Customers: 6667
Experience:  ASE Master Certified, ASE Advanced Gasoline Engine Performance
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Car starts when cold, runs for a very short spell, then

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Car starts when cold, runs for a very short spell, then quits. Will not start again. If lucky, car will do the same next day.
JA: Have you checked the battery, particularly the terminal connections? Are they corroded?
Customer: Yes ground is corroded; however, no problem turning engine over.
JA: What is the model/year of your Ford?
Customer: 1987 Ford LTD Crown Victoria
JA: Are you fixing your LTD Crown Victoria yourself? What have you tried so far?
Customer: A year ago, car did pretty much the same. Mechanic found small relay in computer sticking open. It was part of start system for fuel pump.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Not really, other than I suspect the problem may be same as last year.

If the engine cranks and will not start, it is either loosing spark or fuel pressure.

There is a test port on the metal fuel lines to the engine. It looks like a tire valve stem. Press the needle valve down when it will not start and see if you get a large spray of fuel.

Then, check for spark from the spark plugs. Place a known good spark plug into one of the plug wires and place the spark plug on a god metal ground, do not hold it with your hand, and crank the engine. See if you get a bright blue white spark.

If the fuel pressure is gone, replace the fuel pump and fuel pump relay.

If the spark is gone, replace the ignition module on the distributor.

A. Penland and other Ford Specialists are ready to help you
Customer: replied 2 months ago.
Yesterday, same thing happened, however I managed to keep car running, but it had a knock as though it had a spark plug wire off one of the plugs. The car had wires put in last year. I haven't checked all plugs but I did ck #5 cylinder which I normally have problem.
If it continues, I'm going to put it in shop.

Low fuel pressure can cause the knocking noise you hear. Basically it is called spark knock or pre-igintion in the cylinder where the fuel ignites before the spark plug burns it..