☰
GET A QUOTE

Q: Bad gas mileage, high idling

asked by on August 18, 2016

I'm getting really bad gas mileage while driving my truck. It has now dropped to 7 MPG. When I'm driving on the highway, it runs great. However, it is idling high at the 1000-1500 RPM range. When I'm starting it up, especially when it's warmed up, I have to floor the gas pedal. It starts to sputter a bit before it gathers power. I've been told that many things can cause this, from throttle position sensor, MAF sensor to fuel pressure regulator etc. What do you think I should do to improve the gas mileage and overall performance of the vehicle?

Recommended Services

Check Engine Light is on Inspection $94.99 - $114.99 Get a Quote
Car is getting worse gas mileage Inspection $94.99 - $114.99 Get a Quote
Or For Any Other Auto Repairs Get a Quote

Idle speed for your vehicle should be between 725 and 750 RPM. So, it is idling high. Common causes for this include vacuum leaks and a faulty idle air control (IAC) valve. Either of these issues could also affect fuel economy. However, there are many other potential causes as well. The first step is to retrieve any stored Diagnostic Trouble Codes (DTCs) which serve as a starting point for any further diagnosis. I suggest you have a trained professional, such as one from YourMechanic, diagnose your poor gas mileage and repair your vehicle firsthand.

Ford
Idling
fuel economy
throttle position sensors
MAF (Mass Air Flow) sensors
gas pedal
1990
sputtering
RPM (Revolutions Per Minute)
Bronco II
fuel pressure
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Engine knocking and engine light on
Hello. If the Check Engine Light is on, then it would help to know what codes are coming up. The computer codes would help a mechanic find a starting point to determine the problem. From the description of the problem,...
Read more
Engine missing
Misses generally are caused by failing ignition components like spark plugs, ignition coils, ignition wires, etc. But, every once in a while a component like an injector, or a valve spring can fail and cause a misfire similar to an...
Read more
The "hold" light keeps popping up on its own and it causes the car not to get out of third gear.
Try holding down the "HOLD" button for about 5 seconds and this should correct the problem. If it does not, you may have a computer issue that will require diagnosing with a scanning tool. In this case I would recommend...
Read more
Engine knock/pinging
That sounds like a lower end knock. Which would be a rod or main bearing. The first thing to do is make sure it has oil in it. I expect it does since you state the knock goes away when...
Read more
Intermittent starting problem.
Hi. There may be a couple of reasons why this could be happening. There could be an intermittent problem with the starter not engaging when it should be. This is usually caused by a problem inside the starter solenoid. Another...
Read more
Battery shot?
I would not recommend using jumper cables as a means to connect your battery for a couple of reasons. First of all, it can be dangerous as it can create additional risk of sparks that would not otherwise happen when...
Read more
Where is the location of the cabin air filter on a 2002 F-250 P/U, 2-wheel drive, Diesel 7.3?
For some reason Ford used three different evaporator case designs in the trucks this year. The filter will be in one of these three locations. Look behind the glove box and there is a cover on case and filter is...
Read more
2007 saturn vue green line battery replacement
First, you will want to locate the battery on your vehicle. Then, disconnect the negative cable on the battery first. Next, disconnect the positive cable. Finally, remove any hold down hardware and remove the battery. In order to install the...
Read more
Low oil pressure light but full oil.
It is possible that the low voltage from the battery may be altering the reading from the oil pressure sensor. I would suggest manually checking the oil via the dipstick and using that as a reading as to the oil...
Read more

Related articles

The Best Used Cars to Buy If You Just Had a Baby
Having Having a baby will completely change your life. Your activities and hobbies will change. Your sleeping patterns will change. Chances are good that you’ll also be looking for a change in vehicles. You need to ensure that your car...
Read more
The Best Used Cars to Buy to Maximize Resale Value
A A car is not an investment. An investment, by definition, increases in value. A car is a necessary purchase, and it will never appreciate in value, with the possible exception of classics and antiques. So, as a used car...
Read more
Symptoms of a Bad or Failing Air Injection Hose
Check your car's air injection hose for signs of damage. If there are idling issues or the Check Engine Light turns on, you may have to replace it.
Read more

Browse other content

Cars
Services
Estimates
Maintenance