Hello there,

Has anybody encountered or currently having an issue with the fuel system? No engine light or any kind of indicator for example I filled up the tank (max) then a few days later the fuel meter was at the halfway mark. I only drive locally (like from home to work 10-minute drive) I did replace the air filter, cabin filter, and fuel system cleaner but nothing seems to be working. Any suggestion on how I can resolve this situation? Thanks!

 

I would throw something under the car to see if you have a leak at the gas tank or with some of the hoses. If that doesn't reveal anything, I wonder if maybe your fuel sending unit might just be bad.

 

Hello there,

I will certainly do that! right now I am watching videos on how to replace the fuel system unit and fuel injectors and looking for the parts!

 

This would help if you needed to replace the sending unit.

 

If range is suffering, you would think you are running very RICH and you would see an engine check light.

Is someone stealing your fuel?

 

Hello there Alex M.

I threw the cardboard underneath the car and did not see any signs of drips, the video that you have provided does help me to get there but replacing the fuel system I have had no luck finding any videos on youtube videos only see older models (at Gen) and 2nd Gen of MDX not sure if I can use the videos as references to do the job.

 

Hello Tech,

I do not believe so.

 

What year RDX do you have?

 

Let's start at the original post. You are getting into some compicated engine work without showing any codes or issues other than perceived low mpg. If you had issues with fuel injectors, yuo would have drivability issues. If your RDX is running rich, it would throw a code.

What year is your RDX? How many miles are on it? Have you kept up with the maintenance? In those few days of short driving, how many miles did you actually drive?

You've already determine no leaks but again no codes. Before you do anything else, track the mileage for a couple of tanks of gas. Fill up, drive to empty, mark the miles and fill fuel tank; divide the miles by the gallons of gas.

The RDX is not the most fuel efficient vehicle esp. if you are doing short trips. What you are experiencing could be normal.

 

Hello Alex M.

I have a 2017.

 

Hello Dtownfb,

It is 2017, and it currently has 85,000 miles at the moment, I have always changed my oil services, air filter, and cabin filter every 3,000 miles and I also have done my differential fluids at 75,000 miles. I am planning on doing spark plugs, head gaskets, and injector fluids at the 100,000-mile mark. I drive about 3-4 miles depending on the road traffic at the half tank mark, it has reached between 50-70 miles. normally at that mark, it would have been the 150-mile mark. not sure if this helps or not but the MPG stated "13-16" mpg, and the OBD reader that I have did not pick up any sorts of codes.

 

The video I shared was for the 2013-2018 years, so that would be helpful for your vehicle if the fuel sender was the issue.

 

Hello Alex M.

It only shows how to get to it which I have no problem doing the taking off panels/trims but it shows nothing except replacing it, and I do not know too much about how to replace the unit. The only reference that YouTube has provided is the 2007-2013 Acura MDX Fuel Pump.

 

Disconnect the battery for 15 minutes to reset all the computers, reconnect, and see if anything changes. Also, try changing the brand of gasoline you use to see if that makes any difference.

 

Hello Samiam_68,

I will definitely give that a try. I did not really think of disconnecting the battery! I have done 3 different gas stations 1. Cumberland 2. Maple Fields 3. Champlain Farms all have led to the same result.

 

If you haven't changed the sparkplugs at this mileage that could be the culprit. The sparkplugs should be replaced roughly every 45K miles for an optimum engine performance and efficiency. Old plugs surely affect MPG seriously. Also you may consider replacing both upstream O2 sensors.

 

I forgot disconnecting the battery. I had to do this when I bought my 2017 back in 2020, I was experiencing bad mpg too. I disconnected the battery for 30 minutes (I'm sure 15 minutes is plenty) and saw much better mpg as the car learn my driving habits. I would download a fuel tracking app so you can keep track of your mpg. You should see a steady increase for the next 3 or so tankfuls.

 

In cold weather, the engine takes longer to warm up and add that 2 times for taking the car to work and then leaving later in the day. Cold weather can make a car lose 15 to 20% of fuel
mileage as well. If you are driving in cold weather and have the climate control on , make sure that the air conditioner is turned off , or you will be running another power devise that
will cause fuel usage.

 

I've always had my gas mileage drop in the Winter no matter what vehicle I've had. Granted with my CX-5 I do remote start it often in this winter weather, but things like gas being converted to a winter blend also play a role too.

 

This is my real life MPG data ever since I bought my 2015 brand new. You can see the peaks during summers and valleys during winters. Overall MPG over the life of the car is 23.7. All numbers are calculated actuals - miles driven / gallons filled, not what the computer shows (that's usually about 1 MPG higher). To avoid any tank-to-tank fill variations, I use rolling 5 tank averages.