1999 Mercury Marquis Motor Spins over but won't start

LARRY DM

MEMBER
1999 MERCURY MARQUIS
V8
2WD
AUTOMATIC
97,468 MILES

When I spin the motor over it will not start. I've replaced the fuel pump, thinking that was the problem, since I never heard the fuel pump come on while turning the key on. After replacing the fuel pump and still not hearing the fuel pump come on, I jump the fuel pump relay and the fuel pump started working. I tried to start the vehicle with the jumper on the fuel pump relay, but it still would not start. I then changed the Fuel Pump relay with a new one, thinking I had a bad relay, still with the key on the fuel pump would not come on. I then replaced the EEC relay, still with negative results. I then unplugged the crank sensor and plugged it back in, thinking a possible corrosion problem. Whats next to do, I'm thinking it's the power train control module. What do you think.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Cranks but no start condition:

Fuel and Spark:
Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.