newbie needin some help

[scotland200sx]

my 1994 s14 sr20det seems to be getting only 200 miles to a full tank and i can smell fuel when i'm driving around and more so when i first start the car.

what seems to be the rpoblem?

what can i do about it?

[scotland200sx]

my 1994 s14 sr20det seems to be getting only 200 miles to a full tank and i can smell fuel when i'm driving around and more so when i first start the car.

what seems to be the rpoblem?

what can i do about it?

just noticed i had not tigned the petrol cap up after filling up. could this have caused the low mpg since there was no fuel pressure. it would also explain the smell.

[North240]

Most likely not, your either driving the car hard, or its running very rich.

[AAA240SX]

How many quarts was removed from the motor when you did the last oil change? If it is very little you could be burning it...piston ring...

If this is the case you'll notice a discolored exhaust fume (blue).

If you notice that your rear bumper is getting all soiled and dirty then you're just running rich.

[scotland200sx]

after putting the petrol cap on properly the smell seems to have died.

[GLoBaLReBeL420]

i have the same exact problem with my SR.' I replaced 02 sensor(nothing), replaced fule filter(nothing), checked fuel lines(seems to have little cracks here and there, but nothing is leaking when car is running.), i even gapped my plugs to .035 and still i get smells. NO-WHERE NEAR as bad as before, but i still get them. I guess I'm just running rich. (3" exhaust,DP,bov, FMIC, ACV-R,AFC-II untuned, walbro 255, ngk7's iradium.) So, any ideas . . .

[GLoBaLReBeL420]

my next step is to get a FPR and a gauge, and make sure that it isn't a faulty fpr. I am just hoping for a exhasut leak or something. ( I'm also only getting around 14-16 mpg . . )

[North240]

is the afcII untuned or untouched? ie settings messed with at all or everything zero'ed out

[adoboboy]

Wasn't there a problem with s14 gas tanks leaking? I read somewhere that it cracks. If you find a crack, chewing gum can temporarily patch it up.

[scotland200sx]

still getting rubbish mpg. i'm going to try my o2 sensor and clean my throttle body. my fuel lines are coroded but not leaking. at least the smell is gone lol. is the fuel pressure regulator on the right hand side of the throttle body? also what is the EGR and can that be the cause.

lol where is the o2 sensor?

[smily_vigor]

Ah c'mon man, break out the FSM and look. If your smelling fuel is 95% of the time due to a leak. Even though you don't see it dripping it still could be leaking. One place to look is where your feul pump attaches to the rubber lines something could be loose there. Also check that there isn't any extra fuel leaking from where your injectors go on the fuel rail. If it was a break in your exhaust you'd more likely be smelling exhaust fumes and not gas. the bad gas milege could also be due to something as simple a needing a tune up, or a dirty air filter. Start with all the basic stuff then go from there.

The EGR is the Exhaust Gas Recirculating Valve, main purpose is for emissions. You can get all technical about what exactly it does but i'll leave that to you to do some research.

The O2 sensor is usually located on the exhaust line before the cat, pretty much on just about every car. there's a wire runnin from it so it's pretty easy to spot.

[Irukandji]

still getting rubbish mpg. i'm going to try my o2 sensor and clean my throttle body. my fuel lines are coroded but not leaking. at least the smell is gone lol. is the fuel pressure regulator on the right hand side of the throttle body? also what is the EGR and can that be the cause.

lol where is the o2 sensor?


argg...another guy who bought a 240 w/ an sr20 installed w/o any tech knowledge :spank:

theres another cause for bad gas mileage..... HARD DRIVING! did that ever occur in your mind? :hahano:

[wootwoot]

^^^ he is in Europe and the car came with the engine in it...DICK!

exhaust leak would not cause poor gas mileage
a failing piston ring would not cause poor gas mileage, just burning oil and less power

Are your fuel lines clean looking or do they have an appearence of any resiude? The fuel lines wont look wet if they are leaking almost ever because whatever drips will evaporate extremly quickly. That seems unlikely though. How does the car drive currently? You never said if you noticed a good amount of black on your bumper/exhaust as well

[scotland200sx]

argg...another guy who bought a 240 w/ an sr20 installed w/o any tech knowledge :spank:

theres another cause for bad gas mileage..... HARD DRIVING! did that ever occur in your mind? :hahano:


i came here for advice, not to be treated like a clown BY a clown. i do have some knowledge mate but not on this specific car. ill learn as i go along like i have done most of the time. if you dont have anything helpfull to say then dont say anything at all.

[scotland200sx]

checked in the manual and the o2 sensor is on the manifold near the turbo(i think) is this correct?

[smily_vigor]

Yeah that should be it. You can use a flare nut wrench or an adjustable wrench to get it out.

[scotland200sx]

ok i've came across somthing!!

was out today looking over the varous causes, i removed the heat shield over the manifold and found a blow in the manifold/turbo gasket. this blow is BEFORE the o2 sensor so i'm presuming that this may create a false reading and low mpg. i suspected there was a blow on the manifold before as there was a noise coming from there before but its obvious now as i can feel it coming out when i put my hand down there and you can see the gasket has broken away. i was also wondering if this blow would be causing the wooshing rocket sound as the turbo is kicking in.

[smily_vigor]

Your probably right, can you get any pictures? It would be easier to diagnose if we could see it. Leaking air or in the case exhaust will sometimes make a swoosh sound depending on how the break is. If it's something broken or missing then it could very well tricking your O2 sensor. So change that out with the quickness.

[scotland200sx]

O k here are some pictures of the manifold/turbo
http://img.photobucket.com/albums/v716/denzilv6/man3.jpg
http://img.photobucket.com/albums/v716/denzilv6/man2.jpg
http://img.photobucket.com/albums/v716/denzilv6/man1.jpg

[smily_vigor]

Yup it looks like you surely need a new gasket. Also just to confirm that part right baside where the leak is, that's the O2 sensor. You can find the gasket for pretty cheap the problem is taking it off. Most of the time becasue of the heat produced by the turbo and exhaust the bolts are hard to pull. might wanna spray some bolt remover or wd-40 on them and let it sit, just remember it might smoke or smell bad when the engine's started because it's oil based, so a good idea would be that once you get them out, clean off the wd-40 before you go driving.

[scotland200sx]

thanks for the help smily.

ill get that sorted asap and i hope it cures the mpg problem and the noise.

ill forget all the other things until this is done

cheers!!

[smily_vigor]

No problem man, hope this turns out to be the problem, so that you can get it rectified, well if not we'll get some more ideas. Let know how it goes.

[scotland200sx]

ok i got my gasket fixed but i'm still getting crap mpg. i have plugged diagnostic software into it and i'm not getting any fault codes (55) however the o2 sensor signal seems to fluctuate quite alot. the car also runs lean then rich then lean then rich back and forth.

[scotland200sx]

bump!!!!!!!!!!

[xxxjovaxxx]

hey, i think you are having a similar problem to my brother. my brother has a 240SX hatch (KA24E). his car starts at optimal air/fuel, then it slowly goes up to rich. while in idle, the car reaches its richest state, then while driving, the air/fuel bounces back and forth between lean and rich. we are going to clean out the throttlebody and replace the air filter to see if maybe that is doing it, but i think it may be something a little deeper...

[tt99ol]

it sounds like the o2 sensor is doing its job properly, they are supposed to fluctuate between lean and rich rapidly, but if the fluctuation is too slow you would need a new o2 sensor. Do you have an air/feul ratio gauge? if so it should fluctuate fast and consistently, if it doesnt than the o2 sensor could be the problem.

[scotland200sx]

thanks!

i dont know what to do now. ill probebly sell the car if i cant fix it.