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View Full Version : REDTOP ONLY 10mpg!!


vi3tdt2005
11-24-2007, 11:43 PM
so I'm wondering why i get such low mileage per gallon. Its ridiculous!



-I pulled all my spark plugs- they aren't wet or dirty
-sprayed MAF cleaner
-was told by 2 shops that my injectors and FPR are fine
-no indications of gas leaks because there aren't any smell coming from the engine or bottom of the car except for the car running super rich!
-changed timing from 5º to 15º

now im @ half a tank only ran for 50miles


If anyone knows why I'm open to advices and suggestions

thanks,

cronux
11-24-2007, 11:46 PM
get it tuned?

downshift_sideways
11-24-2007, 11:46 PM
stop boosting so much :)

are you running super rich?

use 100 octane :)

MadScientist
11-24-2007, 11:57 PM
stop driving it like you stole it... unless you did!!!
got pics??? anyone one missing this guys car?!?!

-Drew

vi3tdt2005
11-25-2007, 12:06 AM
haha funny but seriously it doesn't get anywhere near 20mpg and smells like gas every time i step out, and i don't boost 24-7 yet still get low mpg

maybe getting a FPR and a wideband will do it?

SidewayZ-s14
11-25-2007, 12:09 AM
stop driving it like you stole it... unless you did!!!
got pics??? anyone one missing this guys car?!?!

-Drew

Hahah, i just picture that. :spank:

eastcoastS14
11-25-2007, 12:23 AM
yeah lol get it tuned....my sr got great gas milage out of boost 740cc injectors and all

DALAZ_68
11-25-2007, 12:27 AM
yeah bro u needa get that baby tuned...do it b4 u regret it

DOOK
11-25-2007, 12:41 AM
with mods he has listed I am doubting it's a tuning problem... he's running a stock setup. I'm betting either fuel pressure regulator and/or leaky/stuck injectors.

S14DB
11-25-2007, 02:03 AM
Walboro will kill the stock FPR.
http://projectnissan.com/shopping/pc/viewPrd.asp?idcategory=30&idproduct=721

PhilthyS13
11-25-2007, 02:26 AM
If your O2 sensor is shot, your car will run rich.

McRussellPants
11-25-2007, 02:48 AM
It smells like fuel

+

Zilvians are dumb as bricks.


=


Fuel Leak.

brndck
11-25-2007, 03:26 AM
ya get a fuel pressure gauge and make sure u aren't leaking past your orings in your fuel rail. and then get a tune. and if you can get access to consult or something similar and maybe monitor your o2 patterns.

S.ONE.THREE
11-25-2007, 04:01 AM
Check your fuel lines, mine was geting around the same got my car up on a lift well it was running and the rubber fuel lines that go to the fuel pump where leaking like a bitch and i never noticed because fuel drys up in mins.

str4g63
11-25-2007, 06:40 AM
Did you replace the O -ring gasket when you did the fuel pump since it smells like gas. Check your resistance on you injectors and your fuel pressure. Does the car run smooth on and off boost??

SHIFT_*grind*
11-25-2007, 07:46 AM
with mods he has listed I am doubting it's a tuning problem...

For real. "Get it tuned!" For a stock swap? Come on.

Replacing your O2 sensor might help, but yeah, it also sounds like you've got fuel issues. Stick a fuel pressure gauge in there and check your fuel pressure (should be ~36 with the vacuum line attached to the FPR, ~43 with it disconnected), and if it's off, find yourself an adjustable FPR. Pull your injectors and check your o-rings, replace them if they look worn (hell, replace them anyway while the injectors are out, costs like $12 for all 4).

How does the car run? Good power? Any hesitation, backfiring, bucking, etc etc?

motorsnail
11-25-2007, 11:26 AM
sounds like he doesnt have a gas cap or his fuel system isnt air tight. Gas evaporates supa fast like magic.

Jbma327
11-25-2007, 11:53 AM
Are your injectors stock? What kind of ecu do you have? Like motorsnail said your gas tank might not be air tight. check you gas cap and if your trunk smells like gas then you might also want to check you fuel pump housing seal.

fliprayzin240sx
11-25-2007, 03:55 PM
o2 sensor, nuff said...

DOOK
11-25-2007, 06:17 PM
o2 sensor won't make it get that bad of mileage... with the heat created by most SRs a lot of o2 sensors are shot anyways...

motorsnail
11-25-2007, 06:39 PM
o2 sensor won't make it get that bad of mileage... with the heat created by most SRs a lot of o2 sensors are shot anyways...

Yeah he has a leak I dont think there is anyway a stock SR could get 10 mpg and not be about to blow up if its running that rich:tweak:

burnsauto
11-25-2007, 06:40 PM
it shouldnt be the o2 (but i would look into it just to make sure) i've run without my o2 sensor plugged in and didnt get that bad of gas milage.

vi3tdt2005
11-25-2007, 08:01 PM
I haven't seen any gas spraying so it's most likely not a leak, going to invest in an adjustable FPR might be the best way to conserve gas.

thanks for all the inputs

motorsnail
11-25-2007, 08:09 PM
I haven't seen any gas spraying so it's most likely not a leak, going to invest in an adjustable FPR might be the best way to conserve gas.

thanks for all the inputs

It doesnt have to be spraying could just be old fuel lines got little cracks and what not. It will just come out a little when it primes then start leaking slowly while its running it. leaking little bits + evaporation + high air fuel ratio= 10 miles a gallon. It would have to be running really rich for that just to be the problem lots of smoke and fuel out the exhaust

SexPanda
11-25-2007, 08:15 PM
maybe a good ol fashion tune up. My KA has been getting shitty mpg lately too. lik 15 ish on a more or less stock engine thats been well maintained. i had a broken fuel injector. Serial, broken, as in cracked. i never even noticed.

Anyhow, just check the small shit before you get all this new shit. it could be plug gap combined with bad wires, combined with all sorts of small shit that happens, combined to make a big problem. A tune up couldnt hurt either.

LimitedEdition
11-25-2007, 08:18 PM
i had a car that had a bad fuel filter. ended up fouling out the plugs. i changed the filter and still shitty gas mileage.

changed the plugs and gas mileage went back to damn near perfect.

other then that, idk.

Z33dori
11-25-2007, 09:09 PM
my Sr get about the same around town as my ka.....and way better on the highway

garbury
11-25-2007, 09:17 PM
yeah man 10 mpg is absolutely horrible. I think I got like 13 at my worst and i was running like a 10:1 AFR at all times on 850CC injectors. Even now I'm in boost all the time and i get 20 mpg.

Fuel pressure regulator or leaky injectors. Get an inline gauge for easy assessment. Here's my ghetto setup. Summit liquid filled gauge and Ace Hardware tee.

http://i2.photobucket.com/albums/y3/garbury12/100_0336.jpg

s13_slider
11-25-2007, 09:47 PM
I didn't see a leak on my car either.. but I found out I had no O-ring on the top of my gas tank where the fuel pump goes in. At least check it. It takes like 5 minutes and will knock one thing off the list of possibilities. I fixed it, and no more gas smell, and a tank of gas lasted more than 3 days and 100 miles.

SHIFT_*grind*
11-26-2007, 08:44 AM
I was getting a gas smell in the cabin, and found that my fuel pump didn't have an o-ring at all. Replaced it, and voila! No more gas smell.

The thing is though, I was getting 25mpg even without an o-ring. :squint: I have a Walbro 255 and a stock FPR, everything's fine. My swap is a 97-98 blacktop though, so it's possible that my stock FPR is just in better condition since it's a little newer, and hasn't gone bad yet.

1) Replace your plugs, make sure they're gapped correctly
2) Check your fuel lines, make *sure* there are no leaks anywhere
3) Check your fuel tank o-ring, replace it
4) Check your injectors and o-rings
5) Get a fuel pressure gauge. Make sure you do this before you get an FPR. A gauge costs ~$30; FPR costs at least $100, and you're going to need a gauge to adjust your fuel pressure anyway. Better to get the gauge first and then the FPR, rather than wasting $$$ on an FPR AND gauge and finding out that your fuel pressure is fine.

Do all that, see where you're at, and if you're still getting awful mileage, get back to us. :)

punxva
11-26-2007, 08:58 AM
also check your timing, how does is the car actually running?

SoguRacing
12-10-2007, 06:06 PM
clean the maf

vi3tdt2005
12-10-2007, 06:07 PM
-I pulled all my spark plugs- they aren't wet or dirty
-sprayed MAF cleaner for the maf
-was told by 2 shops that my injectors and fpr are fine
-no indications of gas leaks because there aren't any smell coming from the engine or bottom of the car except for the car running super rich!
-changed timing from 5º to 12º

now im @ half a tank only ran for 50miles

any other suggestions would be greatly appreciated.

memphiss13
12-10-2007, 06:19 PM
other things you can do is check for boost/vacuum leaks. if you have boost leaks it will cause your car to be very rich. what does your boost gauge say at idle? is it pulling 20in?

breakingsociety
02-17-2008, 09:34 PM
sorry to bring this old ass thread back alive but i am also experiencing the same problems as the thread starter and wanted to know whats the deal. i have done just about everything the guy did
"-I pulled all my spark plugs- they aren't wet or dirty
-sprayed MAF cleaner for the maf
-was told by 2 shops that my injectors and fpr are fine
-no indications of gas leaks because there aren't any smell coming from the engine or bottom of the car except for the car running super rich!
-changed timing from 5º to 15º"

I still have no good result ..... HOrrible gas mileage and my air/fuel ratio gauge still dipping below the line of rich.. anything else i can do???

vi3tdt2005
02-19-2008, 01:49 AM
Sadly--i'm still getting low mileage as well but i did the math and i'm getting around 17mpg now perhaps setting up an ADJUSTABLE FUEL PRESSURE REGULATOR would help a lot more- but like everyone else i'm BROKE no JOKE

breakingsociety
02-19-2008, 05:34 PM
lol well then wtf do i do? should i take this stuff to a mechanic that works on sr's?? i need this stuf fixed, especially with gas at 3.45 a gallon for premium.....

DTS
02-23-2008, 12:17 PM
I had this problem, I had a bent fuel rail and a leaky injector. The bent fuel rail caused a vac leak past the injector going into the manifold aswell.

sijia10358
02-23-2008, 12:46 PM
i think you needa change the timing to 10º

beeracing s14
02-23-2008, 05:11 PM
take it to marco at sr20store in gardena and he will take a look at it. Get that Hummer performing engine fixed as gas prices are rolling up again!