MPG tanking as of late. Injectors?

So, have them serviced with a cleaning by a major chain auto shop? What else might I have them check for? My 2003 2x4 with 111k is doing some serious gas guzzling recently. Runs good tho. Obvious things taken care of, always have been. That’s what perplexes me. No tools, DIY’er. Limited income.

 

If you don’t send the injectors off to be rebuilt, or replace them, then yes a local garage can probably do an injector cleaning for you. If it’s BG products, I can tell you from experience that it works…I can’t say for sure about the injectors, but the process used to clean the intake tract works phenomenal. A pressurized can will be hooked to your fuel rail, fuel pump disabled, and the cleaner will run through the injectors. The second part involves installing a fogging device in the air intake tract, and letting it run until it’s empty. You can tell a massive difference on a vehicle that is equipped with an egr valve, it steam cleans all the carbon away. If you don’t have an egr, it might be a waste of money. 9 times out of 10, whatever money you spend now is going to be a waste of money, as far as increasing mileage goes. 20~25 mpg on a TRUCK that is not equipped with a cylinder kill function at highway speeds is about as good as anyone can expect, seriously.

 

This thread is a train wreck.

You need to start somewhere. If you don't have tools or are otherwise unable to perform some in depth cleaning on the A/F delivery systems, then something like running SeaFoam (1/3 a can in the gas tank, 1/3 a can in the oil, 1/3 a can through the intake. Oil change within 100 miles) is the best you can hope for.

The real solution is more involved. As the others have eluded to- there are a multitude of reasons why you might suddenly experience decreased MPG. It's unlikely you'll identify a smoking gun.

Check for any pending codes- you may have an issue which hasn't triggered a check engine light yet.

Change your oil.
Clean or replace the air filter.
Clean the MAF (with MAF safe cleaner).
Clean the intake tube.
Clean the throttle body and IAC.
Clean the intake manifolds.
Clean or replace the PCV and EGR systems.
Have the injectors serviced (not by some random local shop- there is a reason MotorWest or LCE are constantly recommended) or replace them. They aren't that expensive and considering their long life span, it's an easy spend.
Replace the fuel filter. I know this is a whole different ball game for the 4 cylinder trucks, but necessary at some point.
Fuel pump/sock inspection.
Inspect and/or replace the vacuum lines.
Inspect the exhaust for leaks- especially around the joins. (I had a small exhaust leak at one of the cross over joins, and had to replace the gasket in there. PITA, but worth it)
Test or replace the o2 sensors.

Spark Plugs & Wires. Not parts store junk- NGK or Denso.

Reset the ECU - Expect bad gas mileage until the computer settles in again.

Once you know you're getting clean air and fuel into the motor, you then have to consider the drive line.

Drain and fill Transmission fluid- Manual is a lot easier than an auto- an auto may require several drain and fills with a final drop the pan and clean the filter.
Manual transmission? Is it time for a clutch replacement?
4x4? drain and fill transfer case & front diff.
Drain and fill rear diff.
Inspect drive shaft(s)- carrier bearing, u joints, slip yoke.
Inspect input and output bearings.
Inspect wheel bearings.
Inspect brakes- are the calipers sticking and causing the pads to drag? same for the drums. Change the brake fluid.
Check your tire pressure and get an alignment / tire rotation.

There also can be things in the engine bay...

Ac, PS, fan belts, etc... Maybe a bad AC clutch? Maybe a bad bearing?
Power system- how is your battery? Alternator, starter? Have you cleaned and inspected the ground wires?

The point is, there is probably not a single issue- it's likely a combination of things from the above list which are adding up to your loss. It's a ~20 year old truck. Toyota's take a beating and are reliable as hell, but at some point, every single item above (and probably a lot more) need to be addressed and maintained.

 

Problem solved. A Pep Boys $89 fuel injector cleaning got me back the 5 mpg that was missing as of late. My hunch was right since I take care of all the little things and my truck had no other obvious signs and ran smooth.

 

My hunch is that there wasn’t anything wrong with it to begin with. I’ve already been there though, so I won’t bring it back up….lol
I’m glad you got your mpg back. Cost me $136.00 to fill up yesterday. I get a solid 15 mpg, with auxiliary tanks 32 gallon capacity total. Gotta run premium because I got a whine underneath the hood. Prices keep going, I’ll bolt my stock intake right back on there, kept everything in case something like this happened. Paid $4.59 a gallon for 93 e10 yesterday.

 

I think my milage is going to improve since I just fixed a P0302 error this last week. I change all my plugs and wires. Since then I've driven it about 80+ miles and my scan gauge is telling me the mpg is up by quite a bit. Check engine light is off, and no more codes are popping up. I'll check the mpg average on the next couple of tanks of gas.

 

You must mean your hunch “was.”

 

Not exactly… I still don’t think an injector cleaning is going to produce a 5mpg improvement. It’s ok though, I could be wrong, it’s your truck and you’re happy with it again, and that’s all that matters at the end of the day.

 

Wait you guys are getting double digits?

 

One time I put some

sounds like you need to go by pep boys and get them to pour a bottle of Techron in your gas tank