marty1966

Not sure if anyone can help or not - I have a 2009 Mustang V6 with 234,000 miles on it! Here is my problem: Sitting in gear at a stoplight or wherever it often goes into a rough idle. It vibrates the car, then comes out of it. I start the car close to 30 times a day. About 2-3 times a day it will start and immediately die. Like its starving for fuel. .I hit the key again and it fires right up. Local dealership couldn't find anything wrong. Stuff that has been replaced: Plugs, Plug Wires, Fuel Pump, MAF Sensor, EGR Valve, Air Filter plus a complete diagnostic check up at the FORD dealer. Any ideas?

99GTvert

Moving to tech..

JJHoover

have you tried replacing the fuel filter, what about the throttle positioning sensor? is there an aftermarket tune? if so try uninstalling it then reinstalling the tune

marty1966

Thanks! I think it has been a little while since the fuel filter has been changed. I kinda forgot about that. And I'll check that sensor, too. Thanks!

marty1966

The fuel filter did help a little bit but it still does it occasional. I'll try the sensor next. Thanks!

Derf00

A dirty throttle plate could cause a rough or no idle situation. At idle the throttle plate is just barely cracked open. Any kind of buildup on the butterfly plate edge or the throttle body near the edge can reduce airflow. Most dealers overlook this. Take you air intake off at the throttle body and have a look at the butterfly. ANY blackness around the outer edge of the butterfly or on the throttle around the butterfly can be the cause.

Take an appropriate throttle body cleaner and spray it out. See if the problem is resolved.