I have a 94 toyota 4x4 with the 22re motor. I have done everything I can possibly think to do. I changed plugs, wires, rotor and cap, fuel filter, new injectors, new intake and air filter, cleaned intake and throttle body, checked for vacuum leaks, replaced brakes, replaced O2 sensor with denso, replaced all fluids from engine to drivetrains with synthetics. With all of this done I still cant get any better then 17 mpg even on hwy driving 55. If anyone has any ideas as to what could be causing this bad mileage I would greatly appreciate it cause I am completely out of ideas.

 

How many miles? What size tires do you have? Have you ever changed the gear ratios?

 

It has 177,000 miles, just put new tires on that are 255/70/r15 and the gears are stock as far as I know.

 

Well, not much you can do there!

Stock for these are 225/75-r15, in some cases 31's if it is an SR5. You're running bigger tires so it takes the engine more work to turn the wheels plus added wind resistance so it further decreases fuel economy.

Also, if you've never changed the gears then you'll notice your speedo is off. It'll say 60 MPH but you're really going 62-63. Just a heads up if you drive around cops a lot.

You can also multiply your MPG by roughly 3.33% to get a more accurate reading. Not going to help much, but a little. So 17 MPG becomes 17.6 true MPG due to inaccurate odometer and speedometer.

Source: http://www.tacomaworld.com/forum/tir...5r15-255-70r15

If you've got some money and feel like throwing parts at it, buy a new DENSO oxygen sensor. An old O2 sensor will kill your mpg's.

 

The wierd thing is the mileage hasnt changed since i just replaced the tires, i had 225s on about a week ago and i was getting the same mileage. And i did replace the O2 sensor with a new denso one.

 

Try some simple tune-up items, you'd be surprised how far it will go on an old engine. Adjust valve lash (warm engine), check cap and rotor, spark plugs, wires. Run injector cleaners through your gas tank. Don't run really thick old (creates unnecessary restriction, 5W20 works in any non-snow area).

Also check fuel filter, air filter, clean throttle body.

Here's a good place to start: http://personal.utulsa.edu/~nathan-b...nce/2maint.pdf

And you might want to replace the O2 sensor, they are supposed to be replaced every 90k miles. So you should be on your 3rd on now if you've had it the whole time.

 

I literally have done everything you recommended. I am running 5w30 oil in the motor right now because i get cold weather up here. I adjusted the valve lash when i did the fuel filter and injectors, I installed flamethrower injectors. I just am wondering if there is something I am missing that is a common cause for bad fuel economy

 

Anybody know anything that i could have missed. I feel like i should definitely be getting better mpg then that no matter what.

 

what was the gas mileage like before you put in the flamethrower injectors?

 

Hmm... now that we see the whole picture that is odd, at least for a 22RE. My 3VZE gets 18ish MPG consistently.

Have you checked for vacuum leaks? If it's drawing in unmetered air, the ECU will compensate with pouring on more gas. I had a valve out of specs and killed my MPG's, dropped from 16 to 13.5 a while back. Take a can of carb cleaner or unlit propane torch and do this:

 

Try seeing if the distributer is set retarded,,,I had the same problem,,was all the way retarded,,it now sits right in the middle of fully retarded and fully advanced,,I was only able to drive to work 4 days on a full tank of gas to work @37 miles each way,,now I get 5 days plus a little bit more,,,

 

Ok so i know this might sound dumb but how do I go about checking this? do I remove the valve cover and look there or where exactly do i look? I am new to this motor and am just learning it

 

anyone?

 

he's talking about ignition timing, which is tested with a timing light. You only need the most basic. http://www.harborfreight.com/xenon-t...ight-3343.html

Much easier than removing a valve cover, and a very basic part of diagnostics.

 

Ok so where should this motor be set at? should it be right at 0, 5, 10?

 

iv never used a timing gun,,,always set timing by ear,,,,,this dose not show you how to set your piston to "top dead center" nor how to time,,,it shows you where you distributer is and the bolt you need to loosen to adjust the distributer ,,here you go.....

 

loosen the bolt and then turn on the truck,,,then move the distributer to where desired,,,

 

Ok i will give that a shot, it seems simple enough. Thanks for the video!

 

Keep us updated!! From my calculations,,,, I get 395 miles on a full tank of gas from chevron gas,,,I don't exceed 65mph,,it take it easy,,,,,I think the truck holds 17.2 gallons of gas,,but when my gas gauge needle is on the empty line I fill it up but am only able to pump in 15.2 gallons at the most,,so I think I could go a little further,,,so 17.2 gallons at 395 miles = to about 23 mpg,,,that's what I get ,,no mods just stock,,on I think 265-70-16 tires,,I think ,,would be almost the same tire size as 31-10.5-15 tire size

 

Ok so i got to checking the timing out and it was set perfect, i jumped e1 and te1 and it retarded the timing to 5 degrees, and when I took the jumper off it went up to right inbetween the two ridges on the gauge which is where i was told it should be. So im guessing this rules out the timing being the culprit for the mileage issue, and since the engine did slow down and retard by jumping the e1 and te1 the tps should be working right? So is there anything else that i can possibly try?