Why is my car burning so much gas while it is idling?

Try spraying carb/throttle body cleaner around the throttle body after the truck is warmed up all the way get someone to sit in the truck with it in drive and there foot on the brake if the idle raises there's a vacuum line leaking or your throttle body gasket is leaking if no increase in idle then thoroughly clean out the throttle body with the spray if it's very dirty inside the varnish from the fuel burning is causing the throttle plate to stick or stay open causing your engine to have increased rpms if your using no name brand gas stop now your killing your motor the major brands have detergents in the gas to keep things clean and better mpgs brands like usa Valero speedway delta liberty are all garbage and should only be used in an emergency situation like you're going to run out also if you are using this junk get 2 cans of Berrimans fuel system cleaner and put it in the gas tank every week for a month or so this will clean out the emissions and gas tank of the dirt and varnish from bad cheap gas I say 2 at a time because the super strength is needed to clean out the gunk and keep using it at least 1 can a month with good higher grade fuel 93 octane for about 2 months after then either stay at 93 or go to 91 or 89 not 87 ///// now the reason for the higher octane fuel is this the higher the octane level the slower the fuel burns and cleaner more efficient burning with the cleaner combination to get out the gunk your truck will run much better and mpgs will increase now post back with progress write down everything you've done and we will take it from there if the problem persists but I don't think so I'm a taxi mechanic in nyc.with 50 years experience so that's where the information is coming from and a lot of the cars have 300,000 to 450,000 miles on them so I would say you should listen to this advice they are ford crown Victorias and are original motors good luck stephen

The obd light with tell specifically what it is, is it gas or rotten egg - the latter means catalytic converter, gas smell probably flooded or not firing on one or more cylinders, need more details. Also, if the light is flashing it's warning of catalytic damage - raw fuel hitting the cat, smell could be heat from cat trying to burn off raw fuel,it will glow red hot.

first of all u need to determine what color of smoke it is and is it coming out of the exhaust pipe. black smoke means excessive gas burning ...blue smoke means burning oil ...white smoke if seen in warm weather conditions means coolant leak into cylinder heads... but as running rich and high low idle might have a vacuum leak or carburetor need new base gasket or rebuilt ... good luck

run your obd codes and see if the code for the idle control sensor pops up , thats what runs your idle

Well since you changed all of those things there are still come other culprits that can cause rough idling. Another cause of a misfire or rough idling may be a coil that is not functioning properly. Also Sensors that are not reading correclty. The most possilble sensors would be the mass air flow sensor, idler air control, or o2 sensor. They all have control in telling your control module how much air is entering in the engine so that it can determine the appropriate amount of fuel that needs to be used with that air for combustion. If its burning a great amount of fuel then the system is running rich. Have your local parts store check to see if you have a codes.

Hope This Helps!

Sounds like you have a vacum leak. Trace the vacum lines under the hood to locate broken or uninstalled vacum line.You can always spray a little brake cleaner in suspect area ,and if the idle goes up, you are close to the problem. Even a intake gasket leak will cause high idle

check for wire that may have been damaged in the prosses

You can have your idle adjusted by your mechanic. It is also possible something is wrong with the device that regulates your idle. Get it checked soon, you will burn more gas and it is hard on your brakes

check throttle position sensor, clean throttle body

plugs new?  fuel filter new?  check fuel delivery to a jar.  500ml in ten sec. is good i recon but specs are better from manual, dont burn yourself gas burns quickly. if pump delivers well then the filter needs to be changed or injectors need cleaning. also check air filter and throttle throat for dirt.