Getting Horrible MPG's
 

Recently picked up this pretty beat S14 and i am in the process of restoring it to sound mechanical performance.
It has a SR20DET all stock as far as i know except the GReddy intake manifold.
I've been getting only the worst mpg, i can smell fuel in the cabin when i have the windows down only, I read a similar thread on here but there are so many different possiblilties but never had a solution posted.
I drive about 2k miles a month so i drive between 55 and 65mph 90% of the time so save on fuel, but i still get just horrible results.
This morning for example i put in $40 91 octane Cheveron an it put me at a hair above half a tank, drove 32 miles to work and now its just a hair above quarter of a tank.
I havent noticed an fuel leaking but it could be evaporating quickly.
The tires are huge (F235 R275) but i know that cannot make it that bad.
I'm going to try and get a oil change and replace spark plugs done asap but money has been very tight, so hopefully next week.
Going with NGK Iridium IX spark plugs and 5w30 full synthetic motor oil

I have read it can be a dirty fuel filter but it only smells like fuel inside the car when windows are down, unless that has nothing to do with it.

Ive also read might be an injector not sitting right.

and also a fuel leak some where.

I want to take it to a dealership and just have them look at it not have them repair it cuz i know it would be damn pricey.
Any other opinions you can share i'd greatly appreciate it

check the oil to see if it smells of fuel

And if it does, what does that mean?
The blow by that comes out of my catch can smells of fuel and oil.

Could be your head gasket if the oil smells of fuel. You may go ahead & give it a tune-up, make sure the timing (15-17BTDC @idle) is good & change the oil- couldn't hurt. Also, are the injectors a purplish color? That's what color the stock ones should be.

Check for vac/boost leaks

Ill check for that thanks, i just rememberd the hood latch broke an i cant pop the hood. fuck my luck

Fix all vacuum leaks. Injectors not install correctly = big vacuum leak = poor MPG

Reset the timing

check CTS

Run copper plugs, BKR7E-11, gapped to .025 for now, until you're sorting the issue out. No use ruining iridium plugs if you're running that rich.


Cliffs: If money is too tight to attack the issue asap, I'd sell the car and get a nice Altima or Sentra that gets 35 mpg and just drive it.

Thanks for the advice ill take everything in except the last part i hate when people tell me that. one step at a time car still drives these nissans are bullet proof

Bullet proof right... but does it run normal/smooth?

don't forget about the o2 sensor. a bad o2 sensor can result is awful fuel mileage.

i think it runs ok, feels like boost doesnt give its full potential all the time. like some times the car pulls hard and wont even be at wot but most of the time it feels sluggish and like its struggling...

where is thee 02 located?

where is thee 02 located? [/quote] the o2 sensor is on the top end of the downpipe, above the flex point. I got the same problem, researching as we speak. if I find out where the problem lies in, I'll let y'all know" just checkout my dip stick and f u h " my oil does smell like gas . . .

the o2 sensor is on the top end of the downpipe, above the flex point. I got the same problem, researching as we speak. if I find out where the problem lies in, I'll let y'all know" just checkout my dip stick and f u h " my oil does smell like gas . . .[/QUOTE]

please do let me know thanks!

but does it run normal/smooth?http://flash.eviziotvreviews.com/9.jpg

Dont put iridium plugs, they cost an arm and a leg and are known to fail earlier than coppers when used with rich mixtures. I cant see why people want to run 60$ plugs when a 10$ one does the job ...

From what you said, i'd say you bought a riced out S14 that needs to be fully rebuilt, which is going to cost money.

I have also read on this forum that removing the EGR valve or using the wrong O2 sensor usually results in running very rich, so that may help you.


But seriously, if you can smell fuel from the catch can, it does not look well ... do a compression check before throwing money at it. Dry, then wet.

i think it runs ok, feels like boost doesnt give its full potential all the time. like some times the car pulls hard and wont even be at wot but most of the time it feels sluggish...

wow this sounds horrible. Do i have to remove turbo to do compression check properly?
What do you mean riced out. if it needs to be rebuilt im just gonna buy another motor.

Forgot the simple fact that your gauge can be wrong also. Fill to the tip top, not a dollar amount. Stop when the pump stops. Then drive till its empty, do the math from there

That's what im thinking but still the rich smell of fuel makes me think otherwise.
I did that when i first got the car a little over a month ago and i got about 230 miles on the tank but im sure i could have pulled off 250 miles because i wasn't sure if the fuel light was working. But its been getting worse since then.
I'm hoping oil change, spark plugs, fuel filter, and some lucus fuel injector cleaner might help. I really hope this isnt too serious

compression test is just about removing spark plugs, removing fuel pump fuse, putting a compression tester in each spark plug hole and try to crank . Repeat for each cylinder, and do it with throttle fully open and battery fully charged. That is a dry test.

If results are low, do the test again but add a spoon of oil in each cylinder (by the plug hole) before testing. That is a wet test. If results are now good, your rings are not sealing anymore (means dead rings, or worn pistons/ bores).

A compression tester is worth maybe 20$, get one.

Another cheap thing to get is a product you add to a sample of your coolant. If it changes color, exhaust gases pass through your coolant (which is bad).

riced => ask google, he will tell.

You wont find a decend SR20 that does not need a rebuild, really.

Thank you very much for the information, what should the compression readings be at?
could have sworn rice is ugly body kit and fart can exhaust.

Something along that line yeah. 275 tires on a beaten up S14 is a good clue, but it may also be a former track car that got sold after getting too many troubles.
Yet a greddy intake manifold is more the sign of a riced car than a tracked car.

Compressions should be around 150psi (10bars). Remember, remove fuel pump fuse, fully charged battery, full throttle, otherwise the reading wont be good.

well it does look like signs of track use but when i say beaten up i meant like paint wise. everything else is in pretty good condition. lol why does greddy manifold make it more signs of rice?

i have an external switch that turns on and off the fuel pump. Thanks for the info im gonna do this as soon as i can open the hood...

My SR is doing the same thing
:/ & I can't figure it out

I sold my 97 SE Kouki.

To get a 97 SE Kouki w/ A SR Needed the turbo to be replaced
Car was running fine when I bought it
Drove it home 75 miles as soon as I got home. Turbo gasket went out
Got A S15 BB Turbo Replaced all turbo Gaskets put the 3inch Exhaust & Fresh spark plugs fresh oil change & still same Doing the same thing
I did a compression test before I replaced the turbo & gaskets it read 160-160-142-160
Still not running right burns gas like crazy & bogs when trying to accelerate
All vacuum are fine no leaks
Car turns off when it reaches a quarter gas tank no fuel light turns on or nothing
Then I add a gallon of gas & turns right up
Still trying to find the problem

Well spartan, Rb26kouki seems like we got the same problem, s h y t! Haha. None the less we must find out what is causing this in our S-chassis, whatever we do Find Out, Experiment or Fail please report back here to the Thread so we can help better understand our Savages Haha" To be Continued.... :rawk:

If we accomplish awesomeness we should meet for some Garbage Burritos lol

well my car doesnt shut off ever but everything else seems identical, there has got to be someone that has ffixed this problems seems very common.

i will continue to post on here, tho this isnt my only problem with the car im kind of scattering around to get things fixed since it is my daily driver.
getting oil changed hopefully this week. then spark plugs or brakes need to be done as well.

ps i love breakfast burritos.

Check your gas tank they usually have a crack leaking fuel

my daily as well, scattering as well... lol

will do asap thanks

another thing id like to ad about how the car runs is the idle gets very high at times but doesnt jump around like a vacuum leak. it idles as high as 1600 rpm then 1100 is the norm

I checked my gas tank & no leaks. i just ordered my AEM A/F ratio sensor for my Gauge to see what its reading. (This is a must for turbo cars)
Also got the ECU checked by a friend of mine & its not throwing any codes

All i want is a nice healthy running SR

Also there are 3 FUEL lines coming from the back of the car to the front
i know one is obviously the feed line connected to the filter & theres a return line connected to the fuel pressure regulator. there is another line that is not connected to anything does anyone know whats its for should it be plugged up?

That's for the charcoal canister. I didn't plug mine. I don't know if that's right but I couldn't find a solid answer.

Because it costs an arm and a leg, and nets 0 gain, unless the engine is already past 450/500HP.

Cylinder 3 on its way out ... compression should be 150psi max, so it is likely the engine has been rebuilt and head was skimmed without a thicker headgasket. Or the compression tester is off.

Try doing the test again on cylinder 3, if compression goes back to normal after some tries you are likely to have worn / sticking valve. If it does not though, check cylinder 3, piston, bore and head for det damage. These engine usually kill the 3rd cylinder first around ringland.

I will run another compression test tomorrow. See what the numbers looks like. Yea, I was surprise to see 160 on 3 of them.

how did your compression test come out?
im thinking of buying a kit from harbor frieght im really worried my engine may be damaged.

I disagree. I believe they are a great addition to any 28RS or 2871r or larger turbo'd SR20. A good friend of mine went from a similar setup as mine and lost a smidge of torque down load (below the usable turbo area mind you) and netted much more HP and torque from 4500rpm+ over the stocker setup.

I wouldn't run it on a stock turbo type setup, but anything beyond that, coupled with nice cams, is a perfect setup if you ask me. I could care less abotu 2500-3500 rpm, the only time i'm there is during mundane driving...whereas when I'm having fun I never drop below 4500 rpm.

100% agree. I think often times new owners tend to forget that the engines they are dealing with are 15 years old, andhave often been abused by 2 owners at this point in their life. Sure people will find a few good ones, but most have toasty rod bearings and washed out ring seal by this point in life :D

The $$$$/HP gain ratio of these is ultra high compared to the $$$$/HP ratio of a bigger turbo, cams or any item that really increase power, that is what i meant. I mean ... they cost 1000$+ delivered. For what ? increased low end torque ? No thanks.

so would you recommend i just rebuild or buy another motor?
I keep debating the issue but im not building a drift or race spec car nor do i have the funds to.
My goal is to have a very fun daily with anywhere from 250-350hp.
I dont plan to keep the car unless i fall in love with it, but i still plan to keep it for 4 or 5 years.

It will always be better to build it then to buy another stock engine with miles already in it. & then you know what you have & know the history of the engine when it's freshly built.

I would think the manifold would lose low end tourque in favor of more top end hp.

On a 2871 and smaller turbo I would think a extrude honed intake manifold would be benificial.
Especially at widening the power band.

I love spartan

There are zero fuel leaks onto the floor. This is getting ridiculous I filled up the tank yesterday morning an 150miles later im on empty

The greddy mani is just a cast aluminium manifold.

I'm aware of that. I guess I need to be more clear. When I said a extrude honed intake manifold I am meaning a extrude honed stock intake manifold.

Changed oil (Amsoil 100% Synthetic 5w30) at a pep boys service station.
Found out a few things, the oil pan is slightly dented inward from the bottom, nothing major at all, the tension rod bushings are busted and getting worse, brakes are fading, and theres a nail in my rear tire which is slowly losing pressure.
but there was nothing else that lead to the cause of why my fuel is so bad, one of the guys there told me it probably needs a tune which would make a lot of sense. gonna invest in that soon. I was thinking of just getting a type of piggy back system like the Apexi Neo afc. Anything else in that price range you guys can recommend?

Also got ny z32 fuel filter today, this things huge! Prolly gonna swap it tomorrow. Gas consumption is still getting worse

So after doing a little reading i think a damaged o2 sensor might be the reason being my horrible mpg's also reading another helpful thread on Zilvia it says there are 2 different kind for the red top, the black top uses the z32 tt. from what i read i need "skinny" version for my red top can someone else confirm before i spend $90 on one.
Here's a link to one i found on ebay.
Genuine Nissan O2 Sensor Skinny SR20DET sr20 Silvia s13 180sx JDM 22690 50F00 | eBay

Did you check ur fpr? Did you try another set of injectors? Is your fuel pump healthy? These are all things you have to do before you waste more time and money.
Solution is get a daily! And yeah compression test it too!
Do you have a multimeter? Check your o/2 sensors!

Check my fpr for what? i dont have another set of injecotrs.
This car is my daily im trying to get it back to par.
Yes i have muiltimeter what should i use it on?
Getting o2 replaced this week.

If you have a stock SR20DET your spark plug gap needs to be 0.036". This will insure all the fuel gets burnt within the cylinder.

How the hell could I know if it has .0036 inch gap?

This is my fuel filter correct? What is that open line underneath? Its a hard line im wondering if its a fuel line also.
http://i365.photobucket.com/albums/o...psc3024244.jpg

I noticed injector 1 doesn't sit as flush as the others, could this be my problem?
http://i365.photobucket.com/albums/o...ps7b998fee.jpg
I tried to pound it back in but I fucken broke the clip.
http://i365.photobucket.com/albums/o...psb27eca84.jpg

bump still need help

It's 0.036". And you pull the plugs out and use one of these...

http://www.expeditionexchange.com/ul...n001%20055.jpg

Which can be found at any auto parts store. Hell, I bet even Walmart has them.

So found this damage from charge pipe to intercooler.
http://i365.photobucket.com/albums/o...ps066a74f8.jpg
I couldn't find on of my damn spare couplers to fit because of this is how the charge pipe and the intercooler meet up.
http://i365.photobucket.com/albums/o...ps33ea7819.jpg
So my nerdy tech brother repaired it for me. Its just a temporary fix but it does the job.
http://i365.photobucket.com/albums/o...psf88a4cc9.jpg
Then this guy hoped in the passenger so I gave him my car...
http://i365.photobucket.com/albums/o...ps8cd708a8.jpg
Lol so I would say 90% of my problems have been fixed just because of that. Not really smelling fuel any more, 100x more powerful I shit u not. And I went from getting 6mpg to about 26mpg all because that stupid rip. So im gonna cut the charge pipe so its straight then use a 90 degree angle coupler.

That open line looks like a vent for the fuel tank.

Yes, these are sold at walmart

Just wanted to give an update, the car has been running great, currently i am getting 26mpg 90% highway driving i can easily get 350+ miles on less then 15 gallons of ARCO 91 octane with chevron a little less. and these results are me driving pretty fast on those days im running late to work. hopefully when i get better suspension an smaller wheels i can get close to 30mpgs!

I had found my problem as well
It was bad engine ground

So my mpgs are going down hill for some reason. Just replaced my alternator an ever since then I im losing about 100 miles a tank or more. the car smells of fuel pretty bad and theres quite a bit of smoke that comes out when I give it some gas.
My mechanic said possibly maf or ecu. And I doubt its the piping again because the power is still there. So any help thanks guys

bump please still need help

HELP ME PLEASE
Just had alternator checked and its fine, maf has been cleaned and it is fine. I need help on what to check for. this is my daily and i am putting in so much money for gas please help!

still looking for help guys, my mechanic suspects engine coolant temp sensor an it is causing me to run super rich.. any ideas?