1999 Mercury Mountaineer Cranks, but won't start

JEFF1548

MEMBER
1999 MERCURY MOUNTAINEER
V8
4WD
AUTOMATIC
110,000 MILES

Starts about 5 out of 6 times. Will always turn over. Once started, runs very smoothly, idles fine and runs fine at speed. When it won't start, we give it a few minutes and most of the time starts within 10 minutes (with various numbers of trys). Have replaced the mass air flow sensor. Does not appear to be related to outside temperature or humidity, as it has started during rain storms and when it's been very cold. Local dealer said he could not repair it unless it wouldn't start for him. And it started flawlessly for 3 days.

Monday, January 4th, 2010 AT 5:24 PM

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Do below to determine if it's a fuel or spark problem:

Cranks and w/n start

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

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Tuesday, January 5th, 2010 AT 1:49 AM