2000 Mercury Mountaineer Q&A
2000 Mercury Mountaineer Question: Why does it turn over, have spark, and fuel pump works, but will not start?
We replaced the crank shaft sensor and it still will not start. The check engine light was on for about 2 weeks before it broke down. We also rented a computer and it is showing no codes found. Could it be as simple as a fuel filter? We have no clue what is wrong with it. - kittywhitty1
HAVE A MECHANIC SCAN FOR CODES THERE ARE CODE(S) STORED IN MEMORY. - pushrod
If you are certain that you have spark and PROPER fuel pressure (the pump running is not enough to go on),and since you must be fairly mechanical to replace the crank sensor, check for injector pulse. Having spark & fuel, but no injector pulse, would indicate a failure of the camshaft position sensor circuit. I don't know what computer you rented, but what is needed is likely a scanner with graphing capabilities. There needs to be certain wave forms generated by both the crank and cam sensors, and they must be in synch, for the engine to be capable of starting on the ignition side of things. Unfortunately, the engine needs to be turning RPM's of at least 675, steady for about 10-20 secs, with no "start" signal present, before the ECM will even consider starting to run "after start" self-checks. However, start by verifying fuel pressure at the port on the fuel rail. If ok, & I think the spec key-on/ engine off, w/o looking it up to be sure, is about 40-44 psi, at a minimum. If pressure ok, since you know you have spark, then take some brake parts cleaner, a flammable spray, and sprayy a couple times in the throttle body or air intake tube every 5 secs while cranking. If it starts, you know the injectors are not doing their job, and the most likely cause, being not 100% sure, but maybe 90%, is the cam position sensor. - MShaw