Laly

iTrader: (1)

any thing i can do to help get better gas mileage. i kind of drive hard sometimes, but i know i should be getting more than 16-18 miles per gallon. how many miles do you guys get on a full tank. i havent got 300 yet.

93 SE

i usually get 280 or a little less,i hit 300 twice,cuz i bought one of those fuel magnets

MaxSE

WHAT?!?!?! you guys get that much? I really got some problem with my car, i only get about 200 miles till the tank is gone... any idea's? I definitely don't drive my car that hard!... CAN SOMEBODY PLEASE HELP ME... at first it was b/c my tranny wasn't working right, my first gear was GONE, and so was my second (almost).. so i had to drive my car hard to get it going 30 MPH, but now that problem is fixed.. and the gas mileage didn't improve.. and i don't drive it hard at all!!.. Does anyone have any idea's on what i can do? Or not do? And the power of my car isn't upto full expectation... only when it is cold... then my car has power!!! the guy told me to put Fuel Injector into the gas tank.. i did it once.. he said i had to do it a few times... and everytime i fill up the car, it feels like it has this shot of power... but as soon as the first quarter of the tank is used.. it is back to having a slow acceleration... after the slow acceleration my car starts going at 30 MPH... it is stock if any of you are guessing, no mods...YET I hope someone can help me with this problem.

93max

so my gas mileage isn't that bad i get about 300 a tank both hiway and city driving

93 SE

i would suggest changing plugs,wires,fuel filter,air filter,clean the throttlebody,and importantly check your tire pressure, ...those are the things i would start with

Nismo87SE

There are a couple of things to do. I would suggest cleaning the throttle body and intake collector (if possible), EGR valve, checking or replace the hoses that run to/from the carbon cansister, checking the fuel pressure regulator, cleaning the contacts on the engine coolant temp sensor, check base ignition timing and o2 sensor, use at least 89-91 octane gas, finally get a fuel filter from a 90-96 300zx (its part# FF651 at autozone).

93 SE

me too,but i still feel like i should get any where over 350

MaxSE

Ok, i should've added in, i always use the best gas, no cheap stuff for my car, the spark plugs were chagned by the previous owner, not to along ago, from nissan so they're stock, not after-market. the o2 sensor i cleaned, did nothin. the fuel filter is new, alot of things on the car is new.. it looked as if though the guy knew about the problem, tried everything to fix it, and it didn't work. The only other thing i could think of was the guy used cheap gas, but that is why i'm using the fuel injector... i'm probably gonna try to replace the o2 sensor instead of cleaning it.... i dont' wanan spend too much money on parts that probably won't fix it. but i'll give those things a try.

flyry110

even with 89 i get like 400 to the tank easy. well, highway driving. with the windows open and sunroof open take 50 miles off that. then with the ac on i get about 330 a tank. this is highway. i get 340ish city.

Czar

I get maybe 16 MPG most of the time, but thats cuz I drive like a maniac and my car has to pump more gas into the engine to keep up with all that extra air getting into my engine. Got Boost???

On the highway before the turbo I got 32 MPG, and now I get maybe 29.

BeatJunky

What's our tank capacity in gallons?

diggityduglas

I can't believe your gas mileage! I thought mine was bad! I get 300 on the nose, every week, and I reset my tripometer with every fillup. At 300, my gas light comes on, but won't stay on. If I run it dry, I can get 330 easy, maybe 340 if I'm feeling really brave, but I don't want to screw up my fuel pump. Anyway, to MaxSE, I know that when my car had serious power loss, I replaced the fuel injectors, and it cleared the probably right up. And I believe the capacity, to whoever asked, is 18 gallons.

mykizism

i get about 350 - 375 normal driving (no full throttle) city driving
i dont know about high way

i get about 290 - 320 driving hard occasionally

i think our tanks hold about 14 - 15 gallons of gas..

DaBoxSE

iTrader: (5)

i am also having this same problem. A few months back, I found a vacuum hose that wasnt plugged into that cylinder-looking thing on the right side of the engine bay. I plugged it in and *woosh* my mileage jumped from about 330 hwy to about 400 hwy. I couldnt believe it... But recently, my mileage has gone to **** again. Im back down to 325 hwy and the hose is still plugged in. But now, I can hear a light whistling sound coming from the engine when I accellerate. I snooped around the engine while it was running to find out where the sound was coming from but I can't find it for the life of me. Anyone have any suggestions? I want my mileage to go back up again. Also, I'm thinking that maybe my injectors may be going bad because when I floor it, it feels like the engine tugs a couple times at low RPMs. How much would it cost to get my injectors replaced?

psyclotran

My current driving range is 400 miles.. I average 25 to 27 MPG in a mixture of highway and city. My driving is more highway than city though.

93max

would it be a power loss or a mpg loss? or it doesnt do anything because my stud broke and now the gasket is getting pushed out casuing that leak.

diggityduglas

Injectors, believe it or not, are actually a pretty easy do it yourself project, as long as you're mechanically inclined, and have a Chilton's. You can buy aftermarket injectors for right around $600, and install them yourself, just be careful that you don't pinch the new o-rings

mykizism

i doubt ur injectors are the problem.. if they were your car wouldnt be running properly

dnas420

i have a 91 se and it gets great gas milage. i get around 450 on a tank. i know this cause i drive to florida from ohio twice a year and it only takes 2 tanks (850 miles one way). my suggestion is:
1)get a new fuel filter
2)get new wires and plugs
3)use chevron with techron fuel system cleaner w/ every oil change
4)get new rotor button and cap
5)octane booster is also good
6)pcv valve replacement
7)get mystery oil addidtive and use in fuel sytem and oil to remove carbon build up (big diff here +5 hp easy if it really neeeds it)
*8)also clean your throttle body with a tooth brush and throttle plate cleaner

all cost for this complete pachage under 100.00 and you will see dramatic diff with all of these together. i am currently using ngk v-power plugs and love them! try this and no BS it really makes your car jump! when i just did mystery oil it made my car make a smoke screen for 5 minutes, im talking like spy hunter smoke. just add about 1/4 of the bottle to your oil then gas and run it kinda hard for 10 minutes. this gets all the carbon build up completly blown off your engine components. Another favorite is the throttle body. its really easy to get to and you'll problably see a black resin build up in it. and once thats gone your throttle plate will move faster which = more hp and response time. well for any more help just email me! hope this helps.

adamlacey

iTrader: (1)

is the mystery oil additive a brand??

I've used Restore brand oil additive, supposed to restore compression etc.
.
Anyone know the difference between these products??

dnas420

http://store.yahoo.com/rodi/chmm013.html this is the link for the mystery oil.

maximan

I get a bit over 300 miles for a tank. Used to get much better than that. Unlike someone said, I cleaned the throttle body and didn't notice any different. Put in new stock plugs but still no improvement. car drives like crap now. I used to like smooth ride of my 90 GXE. Now I've got a new problem with the idle. Cruising around 50mph, without stepping on the gas, the idle needle moves up and down in the range of 1500 and 2000rpm. Does any one know why? I need help desperately. thanks

dnas420

to each there own, i am just trying to help. it worked for me and my friend matts max. but your idle problem could be a faulty idle control valve sensor going bad. mine does a similar problem at 1500 then goes to 1700 then back to 1500. its weird but i think its just that sensor im checking mine tommoro also. i am doing an oil change, fog light bulb replacemnt, rear caliper and pad replacement, and fuel system cleaner, and adding marvel mystery oil. mine will be like new tommoro. my left rear caliper is locking up. only 84.00 a caliper for rear fully loaded.

mykizism

when u put in the new spark plugs, did you gap the plugs right?

adamlacey

iTrader: (1)

Well I got that mystery oil stuff, hopefully it will make as much of a difference as it did for u...

Also the PCV valve... that has something to do with the air intake, ventilating throughout the crankcase or something.. right?

Anyway, did u just go to autozone to get a replacement one, or get one from NIssan dealer... and was it very hard to replace. I have a chilton's -- should I be able to figure it out from that

thanks

dnas420

yes the pcv valve regualtes gas consumption. thus inproving gas milage if you get a new one. hell mine was from 91 when i replaced it 3 months ago, and my fuel filter weighed 3 pounds of solid sludge, it to was original. the mystery oil will be fun , i love racing up and down the highway blinding everyone from the smoke screen i have just sprayed. i have a ractive muffler with a 4 inch tip so it really sprays the smoke out.

maximan

Thanks for replying

I bought the NGK stock plugs from pepboys. I followed instructions from Chilton and Nissan manual to check the gap and it was "right". I did not change the gap at all. is it how it's supposed to be?

can anyone help me on know how to replace the distributor and the rotor? is there a check to see if it needs to be replaced?

eric93SE

iTrader: (1)

I replaced my 02 sensor when it had only 70k on it. I got a 10% inc. in mpg, I went from 20 to now 22mpg (mixed driving)

Bryan91SE

Our fuel tanks have an 18.5 gallon capacity, you won't squeeze much more than 15.5 in (that's my record).

I'm astounded at some of your gas mileages. I consistently get 350 - 375, running 85 mph for long stretches. That is only 24 or so mpg. If I drove it easy, I'd be playing with 400 no problem.

John van de Pol

I got my Max with 9k miles on the clock, and with spirited, but not insane driving could stretch it to 300 miles a tank. When we went to oxygenated fuel, I rarely got over 280. I would put in around 15 gallons every time, so I feel exceedingly lucky if I get 20 mpg out of a tankful.

My recent post on fixing hesitation involved cleaning the throttle body, and replacing a number of vacuum hoses. My experience with bad performance, bad mileage has always been either timing too retarded or a vacuum leak somewhere (if not the obvious like plugs, air filters, or fuel filters)

You can test a vacuum hose by buying some rubber caps that fit the vacuum connector. Disconnect the vacuum hose, and plug the vacuum connector. If the problem goes away, then the hose is probably cracked somewhere. Then you can just replace it. I would not do this to the hose that goes to the brake booster :-). But do check this with a vacuum gauge. If your brake booster has sprung a leak, it has access to a massive, and unrestrained vacuum port. The hoses to the canister, egr valve, and power valve (for VE 5-sp) can be safely diconnected and plugged for a period to test them.

Before replacing the fuel pressure regulator I can recommend you TEST the fuel pressure first (with and without vacuum applied to the FPR). I did not and have an unneeded new FPR in my car.

Good luck,

John

Pickwick

IS the fuel filter from the 300zx a lot better than our stock filter?

roadiusmaximus

...thats what i wanna know...

and another kinda relative topic... anyone have to replace the fuel level sensor? my light bulb works, but the light never comes on, and i know it should have more than a few times.

thank you.

DaBoxSE

iTrader: (5)

Jack McSearch strikes again!

Maximajism94se

i get 20 on city drivin and mid grade, 22 on premium (thats all i use now) and up to 26 when its all highway (again on premium) so go figure...i think im gettin pretty normal mileage but who knows, i usually fill up around 300 or so, but ive gone 360 before, just makes ya wonder about how long the little gas light stays on b/f u really run out.....and yeah 300zx filter? huh??? and changing sensors...anything else that kinda needs 2 b changed on a regular basis besides the o2 sensor???

bjyang

i feel whoever posted this thread. Man, i get only 250 mi MAX. Yes 250 mi. max. i drive 25 mi to skoo and 25 back. D*mn full tank wont even last me a week. But two days ago i put in some fuel injector/carb cleaners. I believe it helped a little. i think could get at least 300 mi on this tank. Im still amazed how some max are getting 350+ mi.
....anyways....how much is anyone paying for a whole tank of gas??
here in milw, wi reg unleaded is 1.37/gal. 20.00 for a whole tank!!
thats a pain.

bj

eric93SE

iTrader: (1)

the max holds 18.5 gallons, the is a good reason for the fact that you can only add something like 15.5 or whatever gallons during a refill. that reason being that nissan knows that there are some real stup!d *****'s out there and that some real serious damage will be done the the fuel pump and injectors if the driver lets the car run out of gas. Thats why you see the last quarter tank of gas drop down real fast on the guage (this is intensional).

roadiusmaximus

i did a search, there, hispeed.


ive read the warnings.

Pervis Anathema

iTrader: (8)

One time I filled up and the car took 18 gallons. no b.s. I was feeling lucky...

maldogs

I can only get 300miles for a full tank if I'm lucky when you guys talk about 450+ per tank that cannot be regular day to day driving. Even if the car was brand new it cannot get more than 32mpg? come on IS the 300zx fuel filter better than the stock

eric93SE

iTrader: (1)

The max is rated at (for my 93 auto) 20 city, 25 highway. In most cases the car is cappable of better than the highway rating b/c it tends to be underated in general.

I am using a K&N fuel filter, it is Billet aluminum and uses a servicable Stainless Steel filter element. It also has an option for racers (I guess for the track) where it will prevent fuel starvation, I'm not using it that way. But I put it in about a year ago and I plan to service it soon. I picked this one up b/c It is rated to pick up particles around 10microns and the better the filter the longer the injectors will last (before there filter screens get filled with the extra fine particles).

Just recently I was thinking about adding a strong magnet either to the bottom of the gas tank or inside (if I was crazy enought to open it up). If I were to open the tank through the pump, I would use a neodymium magnet b/c they are very compact and insainly stronger than a typical iron magnet. But if I attach one to under the gas tank I would probably use an old subwoofer magnet. So you ask WHY, well b/c of the iron particles and other crap that gets put in the tank from the gas station, then these particles get caught in the filter on the fuel pump, this will shorten the pumps life and also affect the cars performance. I don't know if its worth doing or not. I think our tanks are fiber glass, correct me if I'm wrong, but I bet this would definitley be a good idea for people who has steel gas tanks, The inside of those would definitley have some rust or iron particles in there.