Question about 2002 Mercury Grand Marquis
Already changed out plugs,boots,maf sensor,fuel pump fuel filter and tps. diagnostic machine shows different cylinders misfiring at different times
Since it could be several different things in the ignition system, as well as fuel and other things, you may have to get professional help.
Some things you did not mention are the coil, cam and crank sensors, and the computer.
I assume the check engine light is on and the only code you have is a random miss. There are a lot of things to rule out.
Posted on Jan 16, 2013
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Posted on Jan 02, 2017
Start car and use a squirt bottle of water to wet the wires and coil, if you see it spark or run rough one or both are bad, repair the wires first as they are more common.
Posted on Aug 02, 2009
Most parts retailers can tell you what the pressure should be from the pump or what pressure the pump is rated to put out. If pressure is low from the fuel pump- replace it.
Posted on Jan 12, 2013
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