Are fuel injectors a wear item?

Morning all!
'14 EL KR 4WD w/127k miles. No codes/MIL.

Question: Do you consider fuel injectors as a wear item that should be replaced periodically?

I'm struggling to hit double digit MPG in the city, and only reach around 12 on the highway. From what I see, those are both about 25% below where they should be and what others report.
Had a "tune up" done around 110k miles with new plugs, new filter, cleaned MAF, new O2s, fresh fluids, etc. etc. Still has stock coils.
Tires are stock Michelin defenders w/good tread. No lift.
Idle is good, plenty of power, no signs of a miss.
My driving is mostly urban/suburban, but when we hit the highway we're cruising @68-70mph for 100's of miles at a time. I've learned to drive with a light foot and really p|$$ off the drivers behind me pulling away from a stoplight.
We're in corn country, so I use E10. While I have my favorite station for convenience, I get the same MPG behavior regardless of where i fuel up.

The exhaust smells rich, like it's from the 1970s, and when I pop the hood I feel like there's an odor there as well.
If I run a bottle of regane through the system, MPG perks right up... but then fades as soon as I fill the tank again.

I'm thinking I have a leaky/weepy injector or two, but with no codes and a smooth idle, it'll be tough to track down if that's the case. I've never considered injectors a wear item - if they don't work, they'll tell you - but in researching I'm seeing places claim that they should be -replaced- every 100k.

So, thoughts? Am I chasing an MPG figure (12-13 city, 16-18 highway) that isn't attainable? Or do I have an issue that needs addressed? If an issue, am I headed in the right direction? Don't want to throw $250 down the drain if injectors are fine, but I'm feeling that way every time I fuel up anyway and single-digit city MPG is making me want to trade it in if I can't figure it out.

Franklin Jones said:

Morning all!
'14 EL KR 4WD w/127k miles. No codes/MIL.

Question: Do you consider fuel injectors as a wear item that should be replaced periodically?

I'm struggling to hit double digit MPG in the city, and only reach around 12 on the highway. From what I see, those are both about 25% below where they should be and what others report.
Had a "tune up" done around 110k miles with new plugs, new filter, cleaned MAF, new O2s, fresh fluids, etc. etc. Still has stock coils.
Tires are stock Michelin defenders w/good tread. No lift.
Idle is good, plenty of power, no signs of a miss.
My driving is mostly urban/suburban, but when we hit the highway we're cruising @68-70mph for 100's of miles at a time. I've learned to drive with a light foot and really p|$$ off the drivers behind me pulling away from a stoplight.
We're in corn country, so I use E10. While I have my favorite station for convenience, I get the same MPG behavior regardless of where i fuel up.

The exhaust smells rich, like it's from the 1970s, and when I pop the hood I feel like there's an odor there as well.
If I run a bottle of regane through the system, MPG perks right up... but then fades as soon as I fill the tank again.

I'm thinking I have a leaky/weepy injector or two, but with no codes and a smooth idle, it'll be tough to track down if that's the case. I've never considered injectors a wear item - if they don't work, they'll tell you - but in researching I'm seeing places claim that they should be -replaced- every 100k.

So, thoughts? Am I chasing an MPG figure (12-13 city, 16-18 highway) that isn't attainable? Or do I have an issue that needs addressed? If an issue, am I headed in the right direction? Don't want to throw $250 down the drain if injectors are fine, but I'm feeling that way every time I fuel up anyway and single-digit city MPG is making me want to trade it in if I can't figure it out.

Click to expand...

I'm thinking you need to do the injectors. Of course, I can't be 100% sure since I can't physically see the vehicle.

there are moving parts inside an injector so they will wear, often it's the rubber seal in the injectors that go bad (age, ethanol, etc) that can cause a small leak and that does lower your MPG. My expedition has over 200K miles and is on the original injectors, but I run additives (Sea Foam) which claim to lubricate the rubber seals!! If your MPG is that low I would see if you can find a shop that can perhaps clean your injectors (might be cheaper than replacing) but it does sound like you have a leak or two from the injectors.

I can’t answer on injectors, however I recall reading a thread here about MPG and O2 sensors. Someone suggested that the upstream O2 sensors impact MPG and a lazy sensor can really hurt your mileage.

I'm averaging 15.x right now in my EL with a similarly light foot and similar tires (Michelin X LT, the club version of the LTX), so you do seem a bit low. I would start by ditching the E10 and seeing what kind of mileage you get with standard 87.

It is not the e10. I can't say what your issue is, but my 2013 with 120k is easily attaining the mpg you are shooting for. E10-E15 here with a tank of e85 every one in a while. All stock with the same tires.

Yes.

I had a 2014 Standard length and still have a 2011 Standard, both with the same 5.4 3V engine. My mileage experience with both trucks is / was similar, 13.5-15 local driving and 16-18 highway, depending on speed and road type.

Would need to hook up a scanner and check your fuel trims to see if any problems with O2 sensor and/or fuel injectors.
Fuel trims out of spec will be obvious on scanner that has the capability. Problem with replacing those fuel injectors is very expensive and you don't want to go cheap. Only wear item on injectors is just the internal spring, they should last a million miles easy. That however doesn't mean they wont be dirty, clogged or not working properly (leaking). Better to re-do them if you don't replace with OEM.

But wont need to do any of that if you look at fuel trims and they are within spec.
Things that can put them out of spec is leaking injector, vacuum leak (un-metered air), plugs, o2 sensors etc.

Also there is a difference between E10 and regular gas in mpg.

Below shows what your mpg should be with new vehicle.

So I finally had the chance to put a scanner on it, and fuel trims were good.
Bank 1 short term bounced between -7 and +4
Bank 1 long term was pretty steady right around -3.6.
Bank 2 short term bounced in the same range.
Bank 2 long term bounced between -1.8 and -3.2.

While those both indicate I’m running a little rich, it’s not rich enough that I’m losing 25% off what I should see.

O2s were changed as prevention about 15k miles ago w/OEM.

Thoughts?