I'm gettin 12mpg help!!!

[iLLuSi0nS]

Hi, I bought a 1999 4runner 2wd automatic 6cyl. with 130k miles on it

I am getting like 12mpg 13 if I am lucky and drive mostly highway.

I replaced the o2 sensors (both) thermostat got oil change fill it up with injector cleaner every fill up, bosch platinum dual prong spark plugs...and no difference in the mpg

My mechanic said its most probably due to a pressure loss in the fuel injectors. I told him that when I start my car after being off for many hours, when I turn the ignition, it spins 4 or 5 times before it turns on. My air intake filter is clean, and all I have left to do is replace or really clean out the injectors and get a new fuel filter.

My sister has the same car but hers gets like 20-21 mpg, and her ignition turns on on the first click

What do I do?

I have read these forums (awesome place) and most people say slow down, clean MAF syntethic oil, tire pressure, but its not normal to get 12mpg on a 6cyl 2wd 4runner.

Also, I only can fill up 14gal in my tank, is that normal?

Should I replace my injectors? get new spark plug wires? Its time to get new tires, what should I get?

Thank so much for your advice, anything will help from all you 4runner guru's

 

[fightman80]

My 98 4WD 4runner does the same thing when I start it. I thought it might be the timing, but was not sure. I'm definately interested in finding that one out!

As for the tires, what kind of driving do you do? Any Off - Roading? If it's mostly a pavement cruiser, I would go with Mickey Thompson BAJA ATZ. I bought a set last year, and loved them. Very nice ride, and quiet on the road. If you like the OFF Road look, MAXXIS BIGHORN Mud Tires look great! I bought a set this year and love them. They are the complete opposite of the Mickey Thompson's. They look great, are noisy, ride kinda ruff, seem to give crappy mileage, but work great in the mud! It really depends on what you do with your truck. I heard Micheline's are a great tire as well. If you're doing mostly Highway, and don't want an aggressive looking tire, than a Touring Tire will do the trick. And again, the Micheline's are really nice.

I hope this helps you a little.

 

[drmorbius]

Change those Spark plugs. Bosch plugs suck on any vehicle. Platinum plugs suck on 4Runners. Get some NGK or Denso plugs.

:iagree:Get rid of those plugs!

 

[shawnstcyr]

Your fuel filter would do that to you. When you replace it, place a rag over the inlet and blow through it. This will show you how clogged it was. You can blow through the new one first as a comparison. I'd bet you will have some good restriction and blow some nasty crap out of there.

 

[2000runr]

I have been running cooper discoverer atr's for the last 10k miles, love them. great wet traction in rain, incredible in snow, and very quiet on hwy.

 

[TC4Rnr]

here is a list of some relatively cheap things to do,

step one:Seafoam,

Next: Change the following with OEM parts based on your VIN#, Fuel filter($40), plug wire, plugs(NGK or Denso) $60, gas filler cap $25.

clean the throttle body.

drive line fluid: diff, tranny.

Grease these damn zerks on the drive shaft.

cooling fan clutch.

Synthetic motor Oil.

OEM injectors are about $150 each, so that should be your last choice, plus it's not a simple job. you can get them rebuilt about $20 each, Witch Hunt is a pretty reputiable place to go. just google it.

 

[techno]

Also, I only can fill up 14gal in my tank, is that normal?

The tank is 18.5 gallons. The max I have ever put in is 16 gallons and that was after doing 60 miles with the fuel warning light on. It all depends on when you fill it up after the light comes on. If you're filling up within 10 miles or so after the light comes on then 14 gallons sounds about right.

Also, there's no need to run injector cleaner ever fill up. Once or twice a year is good enough.

 

[Pikeman]

I have been running the Michelin LTX's and they are a great all season tire and have even put up with the off road abuse, and got 105k out of a set same tire on my other car. The Michelin AT 2 is a little more aggressive but also an 80k tire. Oher brands are great as well just have had good luck with those in the past. Both of those are available through Costco and they offer their road hazard and rotation so can be a good deal.

 

[iLLuSi0nS]

Wow, I love this place, you guys are all so great, thanks for all the replys

From what I have learned, bosch sucks, I will replace with NGK or Densos (which are better?)

I will get a new fuel filter

TC4Rnr, You sound very knowledgeable but I am a noobie and dont understand exactly what you mean. what do you mean by "Seafoam"?

And how would a gas filler cap increase MPG's?

Also, I think my timing belt needs to be replaced. Sometimes when its cold in the mornings, when I turn it on, it makes a squeeling sound like a screaming pig, I am pretty sure that is the timing belt right? It also happens when its really really hot, and I turn on the a/c, it squeels for a split second.

If I do need a new timing belt, is that a reason my MPGs are so horrible? Would replacing the timing belt help?

Also, would replacing the timing belt fix my ignition problem as well, like I said, it takes like 4 or 5 seconds to turn the car on, but once its on and I turn it off and turn it back on, it ignited instantly.

Thanks for the help guys, whats the ultimate best fuel injector cleaner? Or are mine so bad that they need to be replaces/rebuilt, I heard there are some narley cleaners that will like wipe anything off anything.

 

[Pikeman]

Do a search for seafoam, it is one of the more recomended cleaners on here. I like Lucas Diesel and Gas injector cleaner and fuel treatment. Also the squeeling belt is more likely your Serpentine belt a.k.a accessory drive belt.

 

[drmorbius]

Wow, I love this place, you guys are all so great, thanks for all the replys

From what I have learned, bosch sucks, I will replace with NGK or Densos (which are better?)

I will get a new fuel filter

TC4Rnr, You sound very knowledgeable but I am a noobie and dont understand exactly what you mean. what do you mean by "Seafoam"?

And how would a gas filler cap increase MPG's?

Also, I think my timing belt needs to be replaced. Sometimes when its cold in the mornings, when I turn it on, it makes a squeeling sound like a screaming pig, I am pretty sure that is the timing belt right? It also happens when its really really hot, and I turn on the a/c, it squeels for a split second.

If I do need a new timing belt, is that a reason my MPGs are so horrible? Would replacing the timing belt help?

Also, would replacing the timing belt fix my ignition problem as well, like I said, it takes like 4 or 5 seconds to turn the car on, but once its on and I turn it off and turn it back on, it ignited instantly.

Thanks for the help guys, whats the ultimate best fuel injector cleaner? Or are mine so bad that they need to be replaces/rebuilt, I heard there are some narley cleaners that will like wipe anything off anything.

The squealing is coming from the accessory drive belt (AKA serpentine belt) or it's guide pulleys. If the timing belt was slipping enough to squeal the engine would stop running

 

[Duhockey]

Change those Spark plugs. Bosch plugs suck on any vehicle. Platinum plugs suck on 4Runners. Get some NGK or Denso plugs.

No Way!! I have Bosch 4 prong platinums in my 4runner, I replaced them back in 2005 and have put about 80,000-100,000 miles on them and the car just now started idling a little rough, so I bought some more and Im gonna put em in prob this week.

 

[iLLuSi0nS]

hmm, now I am getting mixed results, bosch is no good? I use the lucas but it did absolutely no difference. So if its not the timing belt, its the drive belt, would that help with the MPG?

I just dont know what to do, I cant keep getting 12mpg, thats horrible.

 

[3000 FPS]

Do a search for seafoam, it is one of the more recomended cleaners on here. I like Lucas Diesel and Gas injector cleaner and fuel treatment. Also the squeeling belt is more likely your Serpentine belt a.k.a accessory drive belt.

If you decide to take the serpentine belt off spin all the pulleys to make sure that one of them is not starting to freeze up and that is what is causing the squeel that you are getting when the engine is cold.

 

[gonzt4r]

Clean the IAC valve helped me a littlewhen i did it.

 

[TC4Rnr]

gas cap is part of the emission control system, if the seal goes bad, it will mess up the ecu calculation.

forgot about the MAF, have it cleaned carefully will help for sure, it only costs 6 bucks for a can of cleaner and 10 minutes of your time.

another thing to consider is the O2 sensors, they can go bust without throwing a code(CEL), i changed mine(bank 2) after getting 14mpg and that helped me clambing back to 16mpg mark.

2wd auto 3rd gen runners should have better mpg than others, because
a.) 250-300 lbs lighter than 4wd. 2wd doesn't have: transfer case, front propeler shaft, front diff., CV shaft(x2)

b.) lots of them have 3.90 gears.

 

[004Gunner]

Check or recheck the following: Tire pressure, air filter, MAF cleanliness, plugs/wires, and brakes. Bad sensors usually throw codes in my experience but it wouldn't hurt to test them with a multimeter to see if they are functioning within specs. I really think brakes are overlooked with bad fuel economy but it is possible that brake drums have over-tightened shoes or that a caliper piston is stuck pushing a pad against the rotor. This usually only causes temporary poor fuel economy, but worth looking into. And just to put in my experience with Bosch plugs, I have been running Bosch dual electrode platinums for 60K+ miles with no issues.