I’m trying to diagnose a 1997 Mercury Grand Marquis crank no start. I have changed the spark plugs so far. The car started to lose power gradually until it shut off several times and would start right up again instantly. However, now it only cranks no start. Would this be the fuel pump? I’d like feedback before replacing it.
Starting fluid is the easiest fuel system test there is. If it does start, put a fuel pressure gauge on the test port to be sure fuel oressure is good.
Alternatively, remove one spark plug from the engine and connect its wire to it like it was in the engine. Touch the electrode end of the plug to some bare metal around the engine bay or engine to ground it, but NOT near the plug hole (touch it to steel not aluminum) and have a friend crank the engine. You should see a spark on the plug. If not, the ignition system has problems (this test won’t hurt you or anything by the way, but hold the plug by the wire when test cranking, not the plug itself). As a bonus, if you smell gasoline from the open spark plug hole, you know it’s getting fuel.