i had the same problem with it not starting or if it did start then it would shut off...my dad replaced the sparkplugs thinking it was those, nope it wasn't...it was the fuel filter! we replaced it and it worked like new...but now as a few years passed once in awhile when we had some cold nights the next morning it struggles to start. when it did it the last time, we banged on the fuel pump gently with a rubber mallite a few times and it started right up. so my fuel pump might be going. So i would say it could be ur fuel filter or ur fuel pump. i hope this helps u!
Thermostat? or radiator? Greg
Engine idling in park.
Its fuel injected doesnt have a carb.
Low coolant? Cooling system airbound?
Noises are impossible to correctly diagnoise unless you hear them. TAke it to a good diagnoistition.
At 35mph it runs rough. Also when idling it will quit running, sometimes. Does that sound like I need new spark plugs? How many miles are new plugs & wires good for?
Could be an exhaust leak close to the engine or a bad catalytic converter. It also could be a bad mass airflow sensor.
BAd radiator cap, low coolant or (leaking), Bad thermostat, cooling fans not turning on.
the idle is controled by the computer you can set minimum air flow but have to have a scan tool if it is idling to low clean the throttle body of carbon
have they check the timing on it. sometimes when timing is off by a few degrees it would cause both rough idle and backfiring. also check for a dead cylinder.
Loose motor mounts.
my idling on my 2001 ford focus is not idling correct, tried to adjust idling but there is no screw or way to adjust why?