3vz TERRIBLE gas mileage x2
#1
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Thread Starter
3vz TERRIBLE gas mileage x2
I know 3vz's suck in general, but ever since I started driving mine it absolutely sucks, and aggravates me to no end. I hear all the time 3vz's don't get that great of mileage, but mines been running about 8mpgs, I can probably burn a whole tank in about 40 miles if I really stay on it.
I've tuned the truck up with all new plugs, wires, cap, rotor, and air filter. I know I used whatever I got from AutoZone, but I aimed for the good stuff, still not dealer quality. That didn't do a darned thing. Still about 8mpg's. The truck runs totally fine, its quick, peppy, no misses, shifts fine, no hesitation or jerking etc. I must say though, it idles just alittle rough...not so much rough, but it sounds like I have a mild cam. Exhaust smells just a tad rich, but not much.
The plugs are gapped to spec, all the wires are on, nothing backwards, no vacuum leaks, timing is right on (was at 12deg but I went back to 10 hoping it'd bring my mileage up)
So what do you veezee guys do to keep your mileage up? This is my nice truck so it never sees dirt, and I usually keep it below 3k. Lately I've been a grandpa and not even breaking 40mph, mostly open country roads, and still not managing to get more then 130 miles on a full tank. Should I check sensors? electronics? Tweak something here and there?
Oh, and forgot to mention, my buddy just bought a 90 4runner, 3vz, auto, only 180k (mine has 130k) and he's getting about the same mileage under the same circumstances (fresh tune up, timing etc.) and on both our rigs, we randomly smell raw fuel in the cabin every now and then, maybe once every day or two.
Before you ask, I know my 02 is probably no good Would that bring me up to 20mpg if I replace that? HAHA
My rig: 1988 3vz a340h 4x4 (hubs always unlocked) 129k 31x10.50
I've tuned the truck up with all new plugs, wires, cap, rotor, and air filter. I know I used whatever I got from AutoZone, but I aimed for the good stuff, still not dealer quality. That didn't do a darned thing. Still about 8mpg's. The truck runs totally fine, its quick, peppy, no misses, shifts fine, no hesitation or jerking etc. I must say though, it idles just alittle rough...not so much rough, but it sounds like I have a mild cam. Exhaust smells just a tad rich, but not much.
The plugs are gapped to spec, all the wires are on, nothing backwards, no vacuum leaks, timing is right on (was at 12deg but I went back to 10 hoping it'd bring my mileage up)
So what do you veezee guys do to keep your mileage up? This is my nice truck so it never sees dirt, and I usually keep it below 3k. Lately I've been a grandpa and not even breaking 40mph, mostly open country roads, and still not managing to get more then 130 miles on a full tank. Should I check sensors? electronics? Tweak something here and there?
Oh, and forgot to mention, my buddy just bought a 90 4runner, 3vz, auto, only 180k (mine has 130k) and he's getting about the same mileage under the same circumstances (fresh tune up, timing etc.) and on both our rigs, we randomly smell raw fuel in the cabin every now and then, maybe once every day or two.
Before you ask, I know my 02 is probably no good Would that bring me up to 20mpg if I replace that? HAHA
My rig: 1988 3vz a340h 4x4 (hubs always unlocked) 129k 31x10.50
#3
Registered User
With 8 MPG you would almost think there's a leak somewhere. I'm sure you checked.
My 3vze was getting around 14 MPG in town. My timing is also set at 15o BTDC so I'm sure this also affected it.
I put in a Denso o2 sensor about 2 weeks ago (had never been changed).
Its not my daily driver, but I drove it everyday until I got real low on fuel and just filled up last Sunday and now I'm getting approximately 16 MPG.
An improvement that I can live with and I think if I back down on the timing it might squeak out maybe 1 more MPG, but I'm going to leave it as it is, just runs better this way.
Put one in and see what happens. Good Luck
My 3vze was getting around 14 MPG in town. My timing is also set at 15o BTDC so I'm sure this also affected it.
I put in a Denso o2 sensor about 2 weeks ago (had never been changed).
Its not my daily driver, but I drove it everyday until I got real low on fuel and just filled up last Sunday and now I'm getting approximately 16 MPG.
An improvement that I can live with and I think if I back down on the timing it might squeak out maybe 1 more MPG, but I'm going to leave it as it is, just runs better this way.
Put one in and see what happens. Good Luck
#4
Registered User
You're getting like 7-8 MPG. Go buy a Hummer, it'll get better gas mileage!
O2 sensor will help if you think it's bad. They only last ~90k miles. There's many things it could be, any CEL codes? You might need to service your fuel injectors, they could be leaking or spraying instead of shooting a stream causing bad compression. Mine gets 17-18, 90% stock.
O2 sensor will help if you think it's bad. They only last ~90k miles. There's many things it could be, any CEL codes? You might need to service your fuel injectors, they could be leaking or spraying instead of shooting a stream causing bad compression. Mine gets 17-18, 90% stock.
#5
Registered User
Thread Starter
I've been thinking theres maybe a leak, sometimes when I start it cold it'll fire then shut right off before it even begins running, almost like the fuel system isn't holding pressure. As far as the fuel lines and such, I havnt seen any leaks.
#6
When my mileage went to crap and I smelled gas in the cab it was a leak of the pulsation dampener. It started out hit and miss but before I replaced it was pretty strong and constant. Is it stronger on the passenger side? The leak also made it hard to start after it sat overnight.
It is located on the back of the passenger side fuel rail.
You can jumper +B and FP on the DLC and look for leaks.
It is located on the back of the passenger side fuel rail.
You can jumper +B and FP on the DLC and look for leaks.
#7
Registered User
I had a huge gas consumption problem with my 3VZE. and i ended up having tons of problems. Just letting you know this motor will probably never get you 20MPG. I had my engine completely rebuilt and i remplaced all my hoses and sensors with brand new ones right off the dealership parts department. And even with everything ive done i have never gotten better then 16MPG all HWY. My truck doesnt get 40mpg to a tank like yours but it surely doesnt get 20 per gallon either. I range from 13.70ish to 16.03mpg with a mix of HWY and Street. I never drive the truck with a lead foot, i always keep it at 60-70mph, hardly ever need to use 5th because of the speed i go and i usually always keep it at 3k-3.5k RPMS.
Just FYI before you get your hopes up high like i did gaining tons of wishful thinking and hoping for 18-21mpg haha. that was a total downer for me.
Just FYI before you get your hopes up high like i did gaining tons of wishful thinking and hoping for 18-21mpg haha. that was a total downer for me.
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#8
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Aftermarket muffler jobs increase MPGs , mine went up by about 20%
#9
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With my timing at 15 degrees i got a solid 18....but i drive like an old person, shifting at 2k-2.5k and using 5th as slow as i can. My motor isnt even fully rebuilt, only the top end. It has cams, efan, exhaust and an air intake. Other than that im completely stock. With factory timing i got 19-20.
#10
Registered User
With my timing at 15 degrees i got a solid 18....but i drive like an old person, shifting at 2k-2.5k and using 5th as slow as i can. My motor isnt even fully rebuilt, only the top end. It has cams, efan, exhaust and an air intake. Other than that im completely stock. With factory timing i got 19-20.
Last edited by Redeth005; 02-05-2013 at 03:08 PM.
#12
Registered User
Any stored codes?? I get about 18ish mpg... so 8 is absolutely horrible. O2 will probably help a lot. Does the oil smell like gasoline?? Im almost wondering if the cold start injector is stuck on... Any problems with heat temps?? As in the engine still thinks its cold and is still running the cold start?? Just trying to think outside the box a bit to give you ideas. I will definitely do the o2 sensor and check for codes and start from there
p.s. the automatics absolutely suck for getting mpg......
p.s. the automatics absolutely suck for getting mpg......
#14
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Thread Starter
i'm not asking for 20, but if I can get atleast 15 i'd be happy. No codes saved, never thought to smell the oil lol
Exhaust smells like slight gasoline, yes.
I have an aftermarket muffler, its a little dinky glasspack type straighthrough thingy, but its not all that loud, its pretty quiet but sounds good.
I'd give you specs but I don't have any...I trashpicked it
Exhaust smells like slight gasoline, yes.
I have an aftermarket muffler, its a little dinky glasspack type straighthrough thingy, but its not all that loud, its pretty quiet but sounds good.
I'd give you specs but I don't have any...I trashpicked it
#16
Registered User
your first post said you had an auto but your signature says its a 5 speed. So pardon my confusion. Here is what I would do so take it with a grain of salt. I would change the o2 sensor since you said its bad anyway. Get a denso!! Ive heard nothing but complaints about the bosch ones on the 3vze. Then reset the computer and drive it. Still not happy?? set the timing to 15 degrees and open the afm up and adjust the fuel wheel 2 clicks lean. should drive like a champ and get 15-18 mpg.
https://www.yotatech.com/forums/f116...stment-203287/
https://www.yotatech.com/forums/f116...stment-203287/
#17
Registered User
Thread Starter
yup, have a cat. A big one too. I've seen smaller cats on a school bus for petes sake!
how would I come about checking the cloggedness of it?
how would I come about checking the cloggedness of it?
#18
Registered User
Thread Starter
your first post said you had an auto but your signature says its a 5 speed. So pardon my confusion. Here is what I would do so take it with a grain of salt. I would change the o2 sensor since you said its bad anyway. Get a denso!! Ive heard nothing but complaints about the bosch ones on the 3vze. Then reset the computer and drive it. Still not happy?? set the timing to 15 degrees and open the afm up and adjust the fuel wheel 2 clicks lean. should drive like a champ and get 15-18 mpg.
https://www.yotatech.com/forums/f116...stment-203287/
https://www.yotatech.com/forums/f116...stment-203287/
2 different trucks hehe.
Might I add, my 5 speed 3vz was getting about 15mpg 90% off road
#20
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