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2001 Mercury Marquis Repair Question


Topics covered: Engine, Spark, Fuel pump.
Mileage: 42,000 miles.

Asked on July 30, 2011

Hard to start/ dies out

2001 Mercury G.M. 42K miles. Ran great but would not start/run after a brief stop @ the store. Starts but immediately dies out. Happened a few months ago and after a few hours it started right up and ran great till today. No loose connections seen. Plenty of fuel. Passed last emissions test. No dash trouble lights.
I have not run my OBDII yet, so no known trouble codes. Years ago this would have been a vapor lock but this engine is F.I. I'm at a loss for a cause. Any ideas?
Thanks,
Jim
Avatar Asked by Keats

Answer

Replied on July 30, 2011

http://www.2carpros.com/articles/car-cranks-but-wont-start

Next time it refuses to start don't wait for it to make up its mind-do below immediately to determine if its fuel or spark problem

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 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, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if okay-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,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing

Tiny Answered by rasmataz
68 questions asked
Replied on July 30, 2011

Thanks you for the info. I knew it had spark cause it would briefly start up but it then died out. As for fuel, it may have been a pump problem.? I let it sit at the parking lot for about 90 minutes and returned with my OBDII to see what I could find. I tried to start it and it fired right up with out any problems. So I drove it home. No stalling or hesitation. This happened a few months ago and this was the exact same thing. I want to run it till it gets up to normal heat and then park it in the garage and shut it off and then try to restart it. If it will not restart, then I can get a reading of the trouble codes and see if it's a sensor that only fails when it's at normal temperature. Last time I checked the codes with the engine cold, it was all negative. Not a single problem so I'm thinking it needs the engine heat to recreate the cause. Could be a sticky IAC valve ? I'll post my results ASAP.
Thanks again,
Keats

Tiny Response from Keats
1 question asked