stab SOMEONE IN THE FACE! I HAVE TRIED EVERYTHING. Mileage & Performance.

[Anto]

Okay. I'm tired of this 240 miles to the tank crap.

I've searched. Tried everything suggested.

Stock car. 1993 240sx SE with a KA24DE.

New cap and rotor.
New plugs.
Good wires.
New o2 sensor.
New thermostat, water pump and coolant flush.
New PCV valve.
New Fuel Filter.
Injector O-rings replaced.
No apparent fuel leaks.
Coolant temp sensor in resistance spec.
Cleaned IAA/AIV valve cluster via intake line.
Cleaned Air filter & Throttle body.
35 psi tire pressure.
Correct TPS voltage.
Keeping it under 3k 95% of the time.
Timing is at 21*.
Intake resonator removed.
Alignment in spec.
New drive belts adjusted to spec.
Running 0w-30 German Castrol.
Fixed faulty knock sensor harness.
Always run 91 octane Shell or Chevron gas with Lucas UCL.

EGR system seems to be fine.
No vac leaks apparent.

I've gone through each and every single one of these f-ing things. I still get 20-22 mpg.

If anyone has something I haven't covered, please f-ing post it.

Feeling like I want to stab SOMEONE IN THE FACE. :bash:

also, when I reverse, during the clutch release, the RPM's drop down considerably, and it stalls out 80% of the time. Even if I gas it a little more than usual, the idle flucuates and wants to die out.
what the f. someone please help me.

[TurK]

you forgot to buy a hybrid.

[Phlip]

What kind of driving do you do? Is this mostly city driving, or are you putting highway miles on the car mostly? I don't know what year your car is, but I would also like to remind you that you're driving a car with an engine that is likely nearing or over 10 years in age, which PROBABLY has over 100k miles on it as well, you can't realistically expect 35-40mpg, even with minor modifications. That 20-22 is better than some of us actually get.

[Anto]

yeh. hybrids aren't $2700 :(

I know this problem is fixable. I've seen people call out 25-29 MPG. My friend with his '96 240 gets 29 mpg.

[Anto]

I'm doing mostly highway driving. 70~ mph.

Also ran a compression test on the car. 180 across the board.
I'm not expecting some crazy MPG, but from the factory, aren't they rated at 23/28?

[Cutless01]

my 95 puts down about 22-25, most I ever get is about 27 on long roadtrips with cruise on at about 85mph. But then I get shitty gas mileage because I tend to find it necessary to pretend Im at a drag strip at every red light, and I simply must beat the old lady next to me to the NEXT red light, or the monsters will eat me!

[yokotas13]

dude
quit bitching
i get 270 KM per tank STFU lol

[Phlip]

I'm doing mostly highway driving. 70~ mph.

Also ran a compression test on the car. 180 across the board.
I'm not expecting some crazy MPG, but from the factory, aren't they rated at 23/28?
I have yet to see a car with 100k or more miles that still conforms to ANY of it's factory ratings, I still contend that your 20-22 is no anomaly.
... my 25-30, on the other hand, is and did nothing special to get to it, it just happens.

[Anto]

ha
haha
hahaha



*those laughs are really tears.

[Anto]

bleeeeeh. so i'm stuck with crap MPG.

well. time to turn this car into a track whore and get a 92 civic hatch with a D16 SOHC non-vtec motor. 40 mpg! haha.

Crap. if there really IS nothing I can do about this,
I want to pee in someone's mouth

specifically the guys who get more MPG than me. :(




...and the fire department is outside my house. at five in the morning.

[TipStylez]

Wait untill you turbo it =]

[vanish1]

my 96 240 I once got 420ish miles from a highway trip one time, most of the time im in 300s tho

[Quigs]

Do you really expect anything more than like 25 mpg from an S13??? I'm pretty sure our cars weren't built for gas efficiency. Especially since in '93, gas wasn't nearly a big of an issue as it is now.

[nonissan]

while i don't think i would cry over 22mpg, my s13 was getting over 30mpg hwy when she blew up 185k on the clock... my sr usually gets close to 30mpg too. that's running 85-90mph for 5 straight hours.

[DaPCWiz]

22... I get like 26-28 reliably... usually closer to the 28 mark. I've done 31 once. I daily drive on the highway 70-75 mph. The car was getting 21-22 when I bought it...

I did intake/headers/exhaust/high flow cat/ghetto rigged rear o2 sensor (not actually in the exhaust)/manual swap/tune up/z32 fuel filter/28* timing/93 octane/cleaned out iacv/MAF/AIT sensor/seafoam :)

135k miles on her now, 119k when I bought her

my old S14 (factory 5 speed) used to get about 27 mpg regularly as well... it had an intake.. and that's about it.. 50k miles when I bought it... had it till 75k

[FaLKoN240]

I never get good mileage for that long, it usually lasts like 1500k after a fresh oil change, after that, the car goes to shit. I have your problem, but I haven't done much to rectify it, not as much as you anyways.

[orion::S14]

What about transmission and diff gear oil? There's A LOT of drag in those parts, when everything's not lubed up with the good stuff.

MT90 for the trans, 85w90 for the diff (I like Mobil 1).

- Brian

[drift freaq]

well your mileage is not that much off the mark. If your running your air you will lose at least 2-3mpg. I know these things for a fact. After running single cam cars and dual cam cars back and forth between los angeles and san francisco I can say the average mpg for our cars is 25mpg, especially if your running your air. If you don't run air and have an extremely clean engine i.e. good shape you can pull 27mpg. Thats the highest I have ever seen.
On top of that I never run 91 octane gas its always 89 or even 87. Under extreme loads i.e. its hot out with the air running 87 will cause minor detonation. At that point it becomes time for the 89. Overall though your ecu will totally compensate for not running 91 octance its pretty much not needed on a stock engine.
Now if you go Turbo, 91 is the requirment hands down you have no choice. Heh there is something to be said about driving a mildly modified stocker for the sake of buying cheaper gas.

[Gnnr]

What tires do you have and what is the max psi rating on your tire? Also you using the stock wheels? Cruise control really helps too. And I guess if you're really anal you can save some power by using an e-fan?? dunno...

[drew935]

Anto,
sounds normal to me.
I get 20-22mpg with 89octane at 76. You might to run seafoam to clean out the carbon deposits/ buildup. Other than that. Why complain about 20-22mpg? :down:
Make more $ and don't worry about mpg. We drive a sports coupe. :coolugh:

Btw, the best I may have gotten was 24-25mpg. But I don't care much about it as long as the car runs fine.
14yr 240 SE 5spd compared to a 06 Acura TSX = SAME MPG = Engine in good condition

[5t341tH]

hmm your 20mpg still sounds good
my whole tank gives me only 180miles
i noe thats crap
its an auto too and i drive normally, keeping it under 4k

[altitude]

also, when I reverse, during the clutch release, the RPM's drop down considerably, and it stalls out 80% of the time. Even if I gas it a little more than usual, the idle flucuates and wants to die out.
what the f. someone please help me.

Can your rear brakes be sticking?

[trsilvias13]

drive at 55pmh and you will see a difference. DO not use A/c, you will see a difference. Let it roll in neutral more often. There are technique where you can get you mpg up. I read it in the newspaper. There a contest for this kind of thing. I think it call hypermiler or soemthing like that. There is a forum for that too somewhere.

[DaPCWiz]

yeah... u'll be surprised how much of a difference keeping your windows closed makes too. I try to keep my car under 3k rpm as much as possible.

my mpg in the summer is significantly lower when I have windows open / use ac / etc

[trsilvias13]

yeah... u'll be surprised how much of a difference keeping your windows closed makes too. I try to keep my car under 3k rpm as much as possible.

my mpg in the summer is significantly lower when I have windows open / use ac / etc


For those who wants to test this theory out, no need, mythbuster already has.

[DaPCWiz]

For those who wants to test this theory out, no need, mythbuster already has.

i haven't seen the mythbuster episode. But from personally driving 100 miles a day, doing about 75-85 mph (i tend to drive faster in the summer... ::shrug::) I get like 23-24 mpg windows down, 26-27 windows up. I didn't find the a/c to make a HUGE difference though.

[~4N~]

Take out the A/C, gut it, and shift at 2.5-2.7 krmp. I get over 30 mpg.

[SoSideways]

Yeah, I have an SR w/ FMIC, downpipe, test pipe, catback, and Walbro fuel pump, and I got over 300 miles when I fueled up (I only let my gas tank run down to the last 1/4 tank mark).

That was not boosting at all city driving and shifting at 2700rpm.

And BOV never opened :D

[ixfxi]

my KA was never known for good gas mileage. KA's in general suck balls in that sense...

replace KA with SR, get more power and better gas mileage.. amazingly enough.

regardless of what car i drive, i never care about efficiency with gas mileage.. its just silly. roll up your windows and you remove yourself from being able to sense other drivers. down-tune your driving and feather the gas, you are now limping on the road and driving like a pansy. i mean, to me... where i position the car on the road and what rpm i am at, is a huge safety benefit. it now only allows me to be away from certain drivers, but keeps me at a powerband that allows me to avoid getting hit (by a woman driver). :-)

[HalveBlue]

i haven't seen the mythbuster episode. But from personally driving 100 miles a day, doing about 75-85 mph (i tend to drive faster in the summer... ::shrug::) I get like 23-24 mpg windows down, 26-27 windows up. I didn't find the a/c to make a HUGE difference though.

Empirical evidence aside, most studies I've seen (or at least heard about) have shown very little to no difference in gas mileage when windows are rolled down as opposed to rolled up.

But hey, if you think it makes a difference, more power to ya.

[Anto]

I understand the fact that 240's weren't built for efficiency, but I'm expecting a tad more than 20-22 MPG from my car. What I don't get is, everything seems to be in excellent condition with my car - Everything is in spec, and i've replaced many components that get dirty.

The mystery of why some people are getting more MPG than me can *probably* be explained. I know it's an old engine (135k on the clock), but judging by some of the responses in this thread, people have had MORE abused motors than me, and are getting 25+ mpg.. Herein lies the mystery.
Is it engine wear? A dirty component?

I run A/C occasionally to cycle the refrigerant and oil (once or twice a week for a few minutes).
I have *not* changed out the M/T or diff fluid yet, that's next on my list (as soon as I can get the damn stripped 1/2" drive bolt out).
Windows cracked for highway, sunroof open.
Using 180sx type-x (or basemodel s14) wheels on 70% Nitto NT450's, max pressure @ 40psi, 205/60/15.
Rear brakes are good, replaced all four corners a while back, no sticking.

As far as driving style, i'm driving with the pulse&glide technique, but i'm also practicing my heel-toe at some stops. It shouldn't make THAT much of a difference.
I'll try using a lower octane gas & i'll clean out the combustion chambers with an overnight ring pack soak.

Many experienced members on this board have said that 20-22 mpg is normal for our cars. If that is so, I want to know what others are doing to get extraordinary MPG. If it's something that I overlooked that I can change or clean out, i'm going to do it. For me, it's as much the MPG factor as it is knowing my engine runs at it's own 100% efficiency, no matter WHAT the MPG is.

I'm thinking the erratic idle in reverse has something to do with my engine not running right. Until my car runs 100% smooth, I know that there's something that needs cleaning or replacement. I guess that could be the mark for 100% efficiency - a 100% smooth car, with no idling, hesitation, or bogging problems.

Thanks for all the helpful insight, everyone. I'm still trying to get this mystery solved..

[sw20>>s14]

i usually get 22-26mpg, but i drive my car only on weekends so the initial cold start on fridays suck and weekends tend to be more city driving for me...on longer highway trips i have gotten 27-29mpg...29mpg being the highest ive ever gotten and only a one time thing...i keep my engine up to par, but not as much as you have; weird...k, piss in my mouth...

[ronj]

Swap in an SR. I make 280 hp at the wheels and still get 36 MPG.

[mrmephistopheles]

Check for vacuum leaks, try a different MAF, and run 87 octane.

[Dream240]

What mods do you have? Have you checked your fuel mixture? Get it smogged and see what that says too. sounds to me like your running rich.

Also any air or fuel mods done to car will affect the MPG usually in the neg.

[UNITEDMASTER]

stop using premium. the KA doesnt need it.

[drift freaq]

well the pulse glide technique your talking about might be part of your problem. I always use a steady foot. On top of that the gas mileage I reported was in several different 240's (yes I have had that many) not just one. So I would say part of your problem does indeed lie in your driving style.
With AC blasting going 80 mph plus I have averaged 25mph. I have done Los Angeles to San Francisco on anywhere from 1 tank to 3/4 of a tank. Thats 375 miles. Steady foot on the gas. not mashing it down most of the time though not letting off so much either. I have also done that run in anywhere from 4.5 hours to 5 hours flat with two stops. Hahahaha .

I have yet to put the RB car through the paces though I did deliver a RB car up there last year. It did not do to bad, of course I could not resist fucking with a NSX and a Chrysler 300. As well as running up 280 with a Mercedes S600 and boy was he surprised and smiling. Stock looking S13 running with the big boys. hahahhahhha

[KAT]

i get about 22-23 daily driver auto s13, mostly city, and i am not TOO heavy on the throtte. i get about 26-27 long distance, about 80mph avg.
the s14 has gotten as high as about 31-32 light on the throttle, boosting a little here and there to stomp hondas. oh, and it's the ka-t. port and polish helps a bit, as does the jwt ecu (believe it or not, i got better mileage AFTER the jwt ecu was in).

[cmcdougle]

try 17mpg. The engine had 195k, and all the sensors were probably shot. The last major owner didn't do much to the car (including changing the oil. . . or even adding more, for that matter. Moron.). My driving didn't help much either. The engine was pretty much trashed, though, and that makes a huge difference.

[180sExy]

My car is the BEST!!!! she gets about 30 city miles. Its great!!! I love my 240!

[Gnnr]

well the pulse glide technique your talking about might be part of your problem. I always use a steady foot. On top of that the gas mileage I reported was in several different 240's (yes I have had that many) not just one. So I would say part of your problem does indeed lie in your driving style.

Agreed. Try to keep a steady foot.

[corwin]

The best I've got from my car was about 24 mpg, and that was driving from oceanside to Fresno, doing a max of 70, with the windows down.

Normally, I get about 20-22 driving like a bat out of hell, windows up, fans blowing in semi cool air.

[initial_drifter]

i've noticed that i get more miles when i go around 65 rather than 75 area

[Anto]

Okay, here's a smog check sheet from a week ago:
http://img179.imageshack.us/img179/6057/img2723mw9.jpg

I'm not an expert on reading it. Anyone care to decipher the readings?

BTW, I drove 59 miles today on 3 gallons, with a steady foot. Filled up exactly 3 gallons of 87 octane when my gas light came on, drove 59 miles, light came back on. I know the gas gauge doesn't offer precise measurements, but it's in the ballpark.
So rule that one out. Steady foot & low octane still gets me low MPG...

To do next: try a different MAF & recheck for vac leaks. I will report back with results.

[BOROSUN]

thats clean...

[Rayne]

When was the last time you changed your air intake filter? I ask because I did not notice you mention anything about it.

[Anto]

Changed it out less than 500 miles ago. Purolator filter.

[mrmephistopheles]

Adding to Dave's and Gnnr's advice, steady foot wins the race.

Your ECU is designed to constantly adjust fuel settings so that it's being as efficient as it can be. The longer you maintain the same rpm, the more efficient your car will be at that RPM.

I drove from coast to coast twice in my KA24DE/5speed with ~300lbs of cargo and 195lbs of me. Best mileage I got was 31mpg, and I averaged ~80-85mpg while cruising. Windows down most of the time too, except for nighttime.

The trick was to simply maintain even pressure on the accelerator and just make smooth adjustments to it.

The reverse dying thing is probably due to a faulty clutch or something.

[drifter808]

im pulling about 30mpg in my SR. thats driving kinda crazy to.

[dct223]

so how do you measure your MPG??? this is what you should do.. top off your car once... drive normally... when the fuel light comes on.. top off again... get the amount of gas you put in the 2nd time you top off and use the milage on your cluster. and have that as your average...

i get about 25mpg on my s14 and that is not driving it like a grandma... this is mixed highway and city and i keep my windows down if that makes a difference...

i have intake, exhuast, walbro 255, MSD SCI ignition, 3 year old NGK wires, and 1 year old ngk plugs and o2 sensor...

BTW.. MSD def improved my gas milage...

[Phlip]

^^^ I fill the car up, set the trip odometer, go about my life in the car, then the next time I fill the car all the way up again (everytime gas goes into this car, it is a fillup) and divide the miles driven by the number of gallons of gas indicated on the pump.
I do not know what my fuel light looks like.

[drift freaq]

well, if your filling up immediately when your gar light comes on you have almost another gallon in the tank if not a complete extra gallon. The warning reserve on our cars is set at the factory for 1 gallon.
So if your doing a tank fillup and then running it all the way through that variable is involved unless pratice the zen of gas mileage.

Why do I know this. Again because I have driven way to many of these cars and many different ones on long distance runs. I have driven them right down to the bitter end before, for the sake of finding out this kind of info. hahhahhaha ya I am nuts. Some people say, I know how to pratice the zen of gas mileage. I.E. I can drive the car right down to the bitter end and know exactly when its time to pull in and put gas in. hahhahahha. There are a couple of signs you get around a mile before you absolutely run out of gas. hahhahahhahhahha
Trust me I would never do this with a Turbo car but with NA what the hey. :D

P.S. looking at your smog paperwork your engine is in very good condition if its burning that clean. like I said earlier your mileage problems are directly related to your driving style.

[gun]

i dont have tim eto read this whole thread but, try checking your oil. i had the same prob w/ shitty mileage, saw that my oil was low, and my mileage is back to normal. sorry if someone already said i have to get to class!

[drew935]

/\ driving it to the end of an empty tank plugs up your fuel filter faster than normal. No prob if it's a rental :D

[Dream240]

Okay, here's a smog check sheet from a week ago:
http://img179.imageshack.us/img179/6057/img2723mw9.jpg

I'm not an expert on reading it. Anyone care to decipher the readings?

BTW, I drove 59 miles today on 3 gallons, with a steady foot. Filled up exactly 3 gallons of 87 octane when my gas light came on, drove 59 miles, light came back on. I know the gas gauge doesn't offer precise measurements, but it's in the ballpark.
So rule that one out. Steady foot & low octane still gets me low MPG...

To do next: try a different MAF & recheck for vac leaks. I will report back with results.

Here:

Pollutants Produced by a Car Engine
In order to reduce emissions, modern car engines carefully control the amount of fuel they burn. They try to keep the air-to-fuel ratio very close to the stoichiometric point, which is the calculated ideal ratio of air to fuel. Theoretically, at this ratio, all of the fuel will be burned using all of the oxygen in the air. For gasoline, the stoichiometric ratio is about 14.7:1, meaning that for each pound of gasoline, 14.7 pounds of air will be burned. The fuel mixture actually varies from the ideal ratio quite a bit during driving. Sometimes the mixture can be lean (an air-to-fuel ratio higher than 14.7), and other times the mixture can be rich (an air-to-fuel ratio lower than 14.7).
The main emissions of a car engine are:

Nitrogen gas (N2) - Air is 78-percent nitrogen gas, and most of this passes right through the car engine.
Carbon dioxide (CO2) - This is one product of combustion. The carbon in the fuel bonds with the oxygen in the air.
Water vapor (H2O) - This is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air.
These emissions are mostly benign (although carbon dioxide emissions are believed to contribute to global warming). But because the combustion process is never perfect, some smaller amounts of more harmful emissions are also produced in car engines:
Carbon monoxide (CO) - a poisonous gas that is colorless and odorless
Hydrocarbons or volatile organic compounds (VOCs) - produced mostly from unburned fuel that evaporates
Sunlight breaks these down to form oxidants, which react with oxides of nitrogen to cause ground level ozone (O3), a major component of smog.


Nitrogen oxides (NO and NO2, together called NOx) - contributes to smog and acid rain, and also causes irritation to human mucus membranes
These are the three main regulated emissions, and also the ones that catalytic converters are designed to reduce.

Your emissions are pretty good, below average but still good for an S13.

As far as the MPG calculation:

Fill your tank until the auto shut off kicks in (NOTE: This means your tank is full, DO NOT TOP OFF!!)
Reset your mileage gauge
Drive until your fuel gauge reads 3/4 tank full.
Refill tank until auto shut off kicks in(remember don't top off)
Read gallons filled on pump.
Use mileage gauge reading to determine MPG per 1/4 tank
example:
S13 tank = 14.9 US gallons 1/4 tank = 3.725 gal.
Mileage reading = 100 miles

100/3.725 = 26.85 mpg :) This is good mmmkay...?

Love life.

[Dream240]

/\ driving it to the end of an empty tank plugs up your fuel filter faster than normal. No prob if it's a rental :D

Once again another myth...

It doesn't matter when you refill your tank, 1/2 or 1/16. The fuel pump will continue to pump at a constant rate until there is no more fuel, then the car dies and the pump stops pumping. Deposits, if any, can be sucked into the pump at any given time.

Simple solution replace fuel filter at recommended intervals, 30k?, and don't worry about it.

Oh and don't believe every evil car story you read.

BTW my S14 got me 26-28, my S13 gets me about 23-25, older car older engine. Use whatever gas you want

[drift freaq]

Once again another myth...

It doesn't matter when you refill your tank, 1/2 or 1/16. The fuel pump will continue to pump at a constant rate until there is no more fuel, then the car dies and the pump stops pumping. Deposits, if any, can be sucked into the pump at any given time.

Simple solution replace fuel filter at recommended intervals, 30k?, and don't worry about it.

Oh and don't believe every evil car story you read.

BTW my S14 got me 26-28, my S13 gets me about 23-25, older car older engine. Use whatever gas you want

Thank you for responding to the myth. I was about to dispel it but you beat me to it.

[Dream240]

Thank you for responding to the myth. I was about to dispel it but you beat me to it.

Well my reply fingers are fresh since it's been awhile for me on Zilvia.

Oh I almost forgot, the whole octane gas issue is simple.
Higher octane can handle more compression before igniting without the spark, lower octane means less compression.

Therefore a low octane gas in a high compression engine will produce knocking (pre-combustion). Since the KA motor compression ranges from 8.9:1 to 9.5:1 depending on the year, the compression is not high enough to produce a constant knocking. On some models you may get knocking/pinging with 87 octane, if so then upgrade the octane until you no longer hear the noise.

Check out this link alot of info.

http://en.wikipedia.org/wiki/Nissan_KA_engine

The Nissan manual on all 240s recommend 91 octane gas due to a "higher performance engine" but also state in the same paragraph that you can use as low as 87 if that is all you have access to.

FIN

[mrmephistopheles]

I can drive the car right down to the bitter end and know exactly when its time to pull in and put gas in.

Ditto.
I think our tanks are 15.9gal?
I once had to fill up 15.87 or so. I got like 450miles to the tank that time.

[drift freaq]

Ditto.
I think our tanks are 15.9gal?
I once had to fill up 15.87 or so. I got like 450miles to the tank that time.
correct you are kev 15.9 gal. is the factory size. hehehehhehehe

[ixfxi]

Check out this link alot of info.

http://en.wikipedia.org/wiki/Nissan_KA_engine

The Nissan manual on all 240s recommend 91 octane gas due to a "higher performance engine" but also state in the same paragraph that you can use as low as 87 if that is all you have access to.

FIN

dohc, not sohc. you can run the sohc in crack cocain and it will still run just fine.

if you advance the timing and are running a better than stock setup, then go with higher octane. if your POS is stock and is sucky slow and all you care about is mileage, than 87 will work just fine and obviously costs less.

seriously, the KA is such a pig... i always got 17mpg city no matter WHAT i did. auto, then converted to manual. headers, intake, tons of maintenance.. at the end, i just stoped caring. maybe thats why i blew it up.

sr is such an efficient motor, its great. if i were you, i would save every dollar spent on maintenance and upgrades, and just run the KA into the ground. then, when that thing explodes.. install a better motor. :-)

[Anto]

wow! 3x post.


Anyway, I just topped off the tank. 9.xx gallons were left, because I pumped in 6.5.
A full tank adds ~100 or so lbs. It shouldn't affect MPG drastically.

Word on the SR. Turbo + granny driving = Higher MPG. Seeeeeriously.
Gonna report back in a few days on mileage.

Oh, and I also raised the warmed tire pressure to ~41 psi. That should get me some more miles..

and probably into a tree if i'm going too fast..

[dwada]

I found a dealer sticker from a S13 in a junkyard and the dealer sticker said 21city and 27 highway. I usally get about 250-300 something miles to the gallon with my KA24DE. I have a intake, exhaust, and Agency power pulley so pretty much stock KA. I'd say 250 is not bad.

[Gnnr]

Oh, and I also raised the warmed tire pressure to ~41 psi. That should get me some more miles...

Didn't you say the max PSI is 40 on the tire. I say stick to the 35psi you had.

[BOROSUN]

umm i think NOx is nitrogen and varying amounts of oxygen. thats what the X is for. it happens at high temperture combustion, nitrogen forms with oxygen.


i found a good info:

Mechanical failures
In closing, I'll leave you with a pattern failure seen in '85-'92 Nissans, models 240 SX and Stanza, and some Hondas about the same vintage. They have individual EGR passages running to each cylinder. Eventually, some of these passages (one or two) will plug up with carbon while others stay open. The remaining passages receive 4-runner EGR volume, which is far too much and causes a misfire on the affected cylinders. It happens above idle and under load. Sometimes you can unscrew Allen head access plugs to clean out the passages, other times you must remove the upper intake plenum chamber to do the repair.



your car seems it's running fine. time to look somewhere else, like what others has been trying telling you.

btw do you heel & toe when comin to a stop? because i do... bleh :p ahaha

[Dream240]

umm i think NOx is nitrogen and varying amounts of oxygen. thats what the X is for. it happens at high temperture combustion, nitrogen forms with oxygen.


i found a good info:

Mechanical failures
In closing, I'll leave you with a pattern failure seen in '85-'92 Nissans, models 240 SX and Stanza, and some Hondas about the same vintage. They have individual EGR passages running to each cylinder. Eventually, some of these passages (one or two) will plug up with carbon while others stay open. The remaining passages receive 4-runner EGR volume, which is far too much and causes a misfire on the affected cylinders. It happens above idle and under load. Sometimes you can unscrew Allen head access plugs to clean out the passages, other times you must remove the upper intake plenum chamber to do the repair.



your car seems it's running fine. time to look somewhere else, like what others has been trying telling you.

btw do you heel & toe when comin to a stop? because i do... bleh :p ahaha

Okay, I'm not sure what you're disputing....
As with any Algebraic statement "x" always equals the varying unknown.
Algebra 101 my friend. :)

As for the EGR malfunction.....even with the 89-94 OBD-I you will get a CEL with this type of problem. Funny part about EGR malfunctions is that the light will come and go when it feels like it, due to the erratic functionality of the EGR components. If you aren't getting a code or CEL "on" then really all you can do is run a fuel treatment/flush about twice a year and leave it at that until your car tells you otherwise.

I know the old OBD-I systems are dinosaurs but they still have basic performance fundamentals that work just fine when you're trying to zero in on your problem.

"IF IT AIN'T BROKE DON'T TAKE IT APART!!!

[Anto]

But does the fuel treatment even touch the carbon passages that the EGR feeds to?
I'm trying to follow the tubing that leads to where the passages are, so I can feed some cleaner in there.

Changes: I lowered my HOT tire PSI to 36 psi per tire, so cold should be a little less. I also lowered my TPS voltage from the upper .5x to .39 and Seafoamed the car. Three 1/3 cup cycles mixed with Lucas UCL, with the last cycle left in overnight as a ring pack soak.

Most recent fillup using the method dct223 and PHLIP recommended. Fill up, drive, fill up again, divide # of miles to gallons on pump.
I did that, and got:
2.2 gallons to 46 miles, 20.9 MPG (granny driving)
and my most recent one:
3.56 gallons to 70 miles, 19.6 MPG (post TPS adjustment, romping on the gas pedal).

I just seafoamed the car, so we'll see if that gets me more mileage. I'm also going to go for longer fillup intervals.

As a side note, this gives me the chance to see how much gas is REALLY wasted when you race around everywhere. Granny driving vs. pedal to the floor. I'll conduct more experimentation and report back with results.

[Drift Motion]

i get about 25MPG mostly highway, no ac

[Gnnr]

But does the fuel treatment even touch the carbon passages that the EGR feeds to?
I'm trying to follow the tubing that leads to where the passages are, so I can feed some cleaner in there.

Changes: I lowered my HOT tire PSI to 36 psi per tire, so cold should be a little less. I also lowered my TPS voltage from the upper .5x to .39 and Seafoamed the car. Three 1/3 cup cycles mixed with Lucas UCL, with the last cycle left in overnight as a ring pack soak.


Whats Lucas UCL? I always hear bad things about Lucas. If its a fuel cleaner, it will dirty up your fuel filter after running the treatment, so you may wan to change it cycles through. And are you keeping a steady foot while driving now?

[reaxion]

27-30 mpg on my 95 s14...and Ive got 170k+. mostly highway driving, easy on the throttle. I get about 300+ or so miles a tank. I was surprised the first week I had my car. most to date was....350?

[Dream240]

27-30 mpg on my 95 s14...and Ive got 170k+. mostly highway driving, easy on the throttle. I get about 300+ or so miles a tank. I was surprised the first week I had my car. most to date was....350?

Well considering the S14 has a 17.7 gallon tank you should be getting:

17.7 gal. x 25 mpg (est) = 442.5 miles total.

That's provided you run it empty. So I would say you should be close to 390-400 if you fill up right when the low fuel light comes on. It's about 2 gallon reserve once the light comes on so you figure 15.7 gallons used at 25 mpg = 390-400.

Driving habits are the unknown in this logic obviously. So your MPG is more like 22-24. Based on your initial report of 300+ even as much as 350 is low-to-mid 20s.

Sorry to burst your MPG bubble. I would venture to say your average fill up cost is $35 for about 3/4 - 7/8 of a tank. Sound about right?

As far as the negative reports on Lucas....never heard any. I started using Lucas products waaaay back when you could only find it in boat shops...yeah.

And my best experience was with my old 86' Accord LX-i, car had 215,xxx miles when I traded it in and the Honda tech Comp. tested in with an almost perfect result. Car never gave me performance problems. Used Lucas ever since. My S14....230,xxx miles and 170 - 175 across the board at time of death. So honestly I have yet to hear bad stories about Lucas. You got em, post em, love to read em.

[BOROSUN]

Nitrogen oxides (NO and NO2, together called NOx) - contributes to smog and acid rain, and also causes irritation to human mucus membranes
These are the three main regulated emissions, and also the ones that catalytic converters are designed to reduce.



sorry, i forgot to quote. oxygen is the unknown varying number aka oxides or oxidation during combustion.

im not saying he has a nox problem or egr malfunction. im just adding info (maybe it could helpful, ppl with egr problems) since, we were on the topic on emissions.

[deadpirate]

But then I get shitty gas mileage because I tend to find it necessary to pretend Im at a drag strip at every red light, and I simply must beat the old lady next to me to the NEXT red light, or the monsters will eat me!



lmfao


agreed

[Gnnr]

As far as the negative reports on Lucas....never heard any. I started using Lucas products waaaay back when you could only find it in boat shops...yeah.

Yes. Bad.

http://www.bobistheoilguy.com/images/lucas/lucas.htm

And I remember reading it on other pages too.

[Anto]

Nooo no no, not Lucas Oil Stabilizer.

UCL = Lucas Upper Cylinder Lubricant. It's actually good stuff. I'm on the bobistheoilguy forums alot, those guys are f-ing NUTS about fluids pertaining to your car. Really. UCL = +

Foot's still steady.

BTW, After the TPS adjustment (.39v), the car has somewhat of a powerband from 5k-6k. Something i've not felt before with the .5x TPS voltage setting.

[Dream240]

Yes. Bad.

http://www.bobistheoilguy.com/images/lucas/lucas.htm

And I remember reading it on other pages too.

huh....interesting article.

Well, like I said that's the first bad news I've heard about Lucas. Now I can cut it out of my oil changes and save 10 bucks an oil change!!

What about the "High Mileage" oils from Valvoline, etc.? Really make any difference?

[Gnnr]

I wouldn't know, but you can definately find out on that site.

[S13Zilvia_fan]

Is the gas tank any bigger on the S14's? I point this out because some S14 guys are posting that theyve gotten 300+ miles on a tank which is fine and dandy but would be irrelevent if the gas tank on the S14 is bigger than on the S13

[chuy]

16.? some gallons for the S-14 but stock ka24de and I dont granny drive and the best I got was 398 with a 1/16th left highway to the track and highway back so 120 miles and the other 278 was in the city I dont baby mine I try to brake something around the house and not at the track.

[Dream240]

Is the gas tank any bigger on the S14's? I point this out because some S14 guys are posting that theyve gotten 300+ miles on a tank which is fine and dandy but would be irrelevent if the gas tank on the S14 is bigger than on the S13

I already posted this info.....

S13 - 15.9 gal.
S14 - 17.7 gal.

[CylonFrakker]

Quit yer bitching my JZZ31 gets about 10-12 mpg. Trying going 225 miles on a 20 gallon tank. Sheesh freaking whiney babies. Just J/K iget about 2-3 mpg on full boost at 25psi on race gas. Thats about oh i dunno 2-3mpg. So go figure

[Anto]

Another Update:

This is what I don't get. On this tankful, I gunned it everywhere. Shifting at 5-6k rpm, but never actually holding the throttle fully down. Basically romping on the gas pedal. I drove 224.7 miles, and when I went to fill up, it took 10.816 gallons until the pump clicked.
224.7 / 10.816 = 20.77 MPG.

What the hell!? I get very close to the SAME mpg when I drive like a granny. This leads me to believe that my ECU might possibly be stuck running in open loop mode. Either that, or maybe one of the wires leading to the sensors are shotty - but wouldn't that trigger an ECU code?

[Gnnr]

That would happen if you run without a thermostat, but you said you changed that. Yes, that would eventually trigger a code....it should have by now.

[Dream240]

Another Update:

This is what I don't get. On this tankful, I gunned it everywhere. Shifting at 5-6k rpm, but never actually holding the throttle fully down. Basically romping on the gas pedal. I drove 224.7 miles, and when I went to fill up, it took 10.816 gallons until the pump clicked.
224.7 / 10.816 = 20.77 MPG.

What the hell!? I get very close to the SAME mpg when I drive like a granny. This leads me to believe that my ECU might possibly be stuck running in open loop mode. Either that, or maybe one of the wires leading to the sensors are shotty - but wouldn't that trigger an ECU code?

Have you ever unplugged your battery to reset your system? Try that. unplug your Neg battery terminal and wait about 5 min. Reconnect. This will reset your comp.

Drive your car around and redo the MPG test to see if that changes anything.

[Anto]

I reset my ECU after the TPS adjustment, but i'll leave it disconnected overnight now. I'm on a mission to get the MPG problem solved.

More updates to come!

[dannyboi]

maybe clogged fuel injectors?

also try that zMax shit... might work.

[Anto]

A while back my ECU threw code 45 - a leaky injector. I replaced all of them (and the associated o-rings) with injectors from a low mileage 98 KA. Car never leaked fuel on the intake manifold or threw a code after that. I'm also using UCL on every tankful, so the injectors should be golden.

Another small update:
I went on a very "spirited" canyon run tonight. Car was between 4k and 6k for 80% of the time, and I managed to rack up 114.2 miles. When I went to fill up, I got 5.258 gallons.

114.2 / 5.258 gallons = 21.71 MPG.
Haaa ha ha. The more I throttle it, the higher my MPG is - unless....
maybe the Seafoam treatment and Lucas UCL ring pack soak really did something. I'll do another "control" run by granny shifting it for the next 100 or so miles. We'll see how many miles I get.
I'm also leaving the battery unhooked overnight, in an attempt to fully reset the ECU.

More to come!

[skylinekin]

my sohc struggles to get 200 miles to the tank, and i dont drive it very hard at all, all city driving though, and I always have this black crap on my bumper, even though ive done a full tune up and timing is correct.

[Dream240]

my sohc struggles to get 200 miles to the tank, and i dont drive it very hard at all, all city driving though, and I always have this black crap on my bumper, even though ive done a full tune up and timing is correct.

That black crap is from a faulty CAT Converter. Or maybe your not running one at all????

Also how's your oil consumption? How much oil does your car devour in between oil changes? This speaks volumes...

[skylinekin]

doesnt go through oil much at all, less than a quart per change, has perfect compression, you are probably right though, plugged cat, i still have the stock one on there, could this be hurting my gas mileage??

[JesusFreakDrifter]

i thought it was 44psi tire pressure, and if you want 30+ get a corolla or a geo

[Gnnr]

44psi? Are you talking about his tires? They're rated at 40psi MAX. He shouldn't run more than that.

[CylonFrakker]

Is your driving at night or more during the day? If it is at night your headlights are ususally up meaning you just increased your drag. Do you drive with the windows down? If you do the parachute effect takes place and is worse than the 4 @ 40 rule (4 windows down at 40 mph). Also youi have to consider that if your compression is good but you injectors are sticking then you need to consider getting new ones. Also have you bothered to look if you have an unecessary amount of friction in your drivetrain. Check your brakes, check your tranny? What kind of oil do you use? Is it heavy or is it light? City driving makes a big difference. Also are you hauling extra crap in your car, stereo, tools, etc. Do your does seal properly, do you use 93 octane. Ask your self the question you need to ask yourself before posting about MPG. Some of us don't give a damn about MPG but care more about our AFRs. Get a friend with a wideband and check your AFR's Good luck.


P.S. To the dickhead who gave me a bad rep fuck you and I said it was joke you fucking ankle.

[Dream240]

Is your driving at night or more during the day? If it is at night your headlights are ususally up meaning you just increased your drag. Do you drive with the windows down? If you do the parachute effect takes place and is worse than the 4 @ 40 rule (4 windows down at 40 mph). Also youi have to consider that if your compression is good but you injectors are sticking then you need to consider getting new ones. Also have you bothered to look if you have an unecessary amount of friction in your drivetrain. Check your brakes, check your tranny? What kind of oil do you use? Is it heavy or is it light? City driving makes a big difference. Also are you hauling extra crap in your car, stereo, tools, etc. Do your does seal properly, do you use 93 octane. Ask your self the question you need to ask yourself before posting about MPG. Some of us don't give a damn about MPG but care more about our AFRs. Get a friend with a wideband and check your AFR's Good luck.


P.S. To the dickhead who gave me a bad rep fuck you and I said it was joke you fucking ankle.

Hey did you even check this thread? ALL this has been covered.....TWICE, shit 3 TIMES.

And for skylinekin: Yes a plugged cat will hurt mileage and overall power. You are getting more backpressure and less exhaust flow, really just choking the engine. replace it and see what happens...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=002&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=120053107715&rd=1,1

BAM....done.

[skylinekin]

will do, thanks.

[CylonFrakker]

Hey did you even check this thread? ALL this has been covered.....TWICE, shit 3 TIMES.

And for skylinekin: Yes a plugged cat will hurt mileage and overall power. You are getting more backpressure and less exhaust flow, really just choking the engine. replace it and see what happens...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=002&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=120053107715&rd=1,1

BAM....done.


Hey calm down. It was directed to the guy complaining about gas mileage. I basically wanted him to ask himself all those questions and start eliminating the causes bad gas mileage

[Dream240]

Hey calm down. It was directed to the guy complaining about gas mileage. I basically wanted him to ask himself all those questions and start eliminating the causes bad gas mileage

Oh....you're right sorry. :doh: Didn't mean to sound pissed. Yeah it looks like this thread is helping more than one person at a time. I was thinking you were posting ALL over again.....

Peace.

[CylonFrakker]

Oh....you're right sorry. :doh: Didn't mean to sound pissed. Yeah it looks like this thread is helping more than one person at a time. I was thinking you were posting ALL over again.....

Peace.


No P! :coolugh: