Need help with 1996 GST Gas Issue

[romeshs]

Hi guys..
i know gas mileage issues has many threads here, and i have searched almost all i think and havent found a solution for mine. So here goes..
i recently bought a 96 gst with an auto tranny.
i get about 150 miles to 13 gallons.
i have checked for boost leaks as some threads suggested,
but i didnt find any. my car is bone stock, with 69000 miles on the clock.
one issue i did find after going through the many threads was that one of the lines from my BCS had come off. the one that goes to the intake. i cleaned and plugged that back in. i also removed the restrictor.
i have the stock boost gauge on the dash so i dont exactly know how much boost im making, but under hard acceleration, the gauge almost hits the full mark on the gauge.
i have a problem with engine mounts as answers to a previous thread i had started, helped me to understand but i doubt thats the cause for the gas mileage issue.
ive checked everywhere i can think of for leaks but havent found any.
please help guys. this things driving me crazy. cant afford to out that much gas in the damn thing.
not to compare, but i get around 350 miles to 13 gallons on my other car, a 2009 lancer ex. 2.0.
please guys any ideas will help.
thanks in advance.

 

[95GSX19]

check your fuel filter and or fuel pump. you may just be dumping to much fuel. if you are running rich it would be an air to fuel problem. I would pull your plugs and check them, make sure they arent just black and gummed up with crap. I would check your wires and ignition as well. is it hard to start? do you loose power/struggle when you go WOT?? (wide open throttle). Are there any CEL at all??

 

[KieWhitehouse90]

I have a 95 GST Auto, which was also bad on fuel.
Try replacing your o2 sensor, that helped mine a lot, if everythings stock as you said, it may well be the original one and they can go bad, and cause you to run richer.

Also check your side intercooler/pipes/turbo, make sure they are not caked inside with oil and crap from your pcv system, it builds up over time without a use of a small catch tank.
Also check your pcv valve while your at it, take it off and blow through it to check it only allows flow out your valve cover, not in.

Also make sure your BOV recirculation pipe hasn't been blanked off, that will make you run so much richer through loss of air thats already passed your MAS and been accounted for by your ecu.

Besides that, perhaps bad injectors, do you get a strong fuel smell when your driving?

 

[Clutch450]

Just go over the whole car and do a good tune up if you haven't yet.
Check/Replace:
Spark Plugs
Spark Plug Wires
Coilpack
Fuel Filter
Fuel Pump Fuel Pressure Regulator
Clean Injectors
Check Tire Pressure
Boost Leaks/Vacuum
Air Filter

Lots of things can affect gas mileage. The replacement parts may be pricey in the beginning but worth it in the long run if it saves you money on gas everyday.

And it all does depend on your style of driving, staying out of boost saves a lot

 

[romeshs]

@ 95GSX19,
i haven't checked the plugs yet. but there's no issue at all at ignition. starts up as soon as i turn the key. and no there's issue when i go WOT. i can actually see the gas needle drop, but it goes like i stole it, soon as i rev over 3000 and the turbo kicks in. ive pulled all the way upto 170 and still wants to keep going, even though i got a it freaked out as the thing started shuddering when i passed about 140.
(front lower arms are shot)

@ KieWhitehouse90,
thanks. i havent checked any of the things you have said and i will do that tonight.
about the gas smell, yes i do. well not while driving but when i come in and park the car, smells like gas. a lot and it was drivin me crazy thinking i might be leaking gas and was afraid i might blow up!
whats the cause for the strong gas smell?

 

[jpmxrider489]

What's 170? Check and see if you maf is plugged in.

 

[95GSX19]

What's 170? Check and see if you maf is plugged in.

I believe he means 170 mph. I agree ^^^ check your MAF. Always check your 02 sensor that will mess up your fuel for sure. But as stated start with the common easy tune up items. Start checking and replacing if needed. Eventually you will find the issue and be good to go. Keep us updated man we can always narrow it down the more you check. GL!!!

 

[Clutch450]

I'm pretty sure he means 170km/h. Says he lives in Dubai.
Just my opinion.

 

[95GSX19]

I'm pretty sure he means 170km/h. Says he lives in Dubai.
Just my opinion.

AH DERP! I just saw that

 

[romeshs]

Sorry for not mentioning that. Yes I do mean 170 kmph. I checked the MAF sensor and its plugged in. I unplugged it just to see if there would be an indication if its atleast hooked up and immidietly the check engine light came on and went off when I plugged it back in.
Car idles at 1000rpm exactly, no misses or any such issue. Turpo sounds ok, when I'm driving I can hear it spooling and even though its not very loud, I can hear the blow off. Will take a few pics of the engine bay and post it, so that if anything is out of place, you guys can help me identify it? Thanks a million...

 

[95GSX19]

If the car is pulling hard and sounding ok, it might be the 02 sensor right there up front on your turbo manifold. It could also be the fuel filter. I would check both of those really well. Take some pictures of the 02 sensor, let us see what color it is.

 

[isantop]

AH DERP! I just saw that

The stock DSM doing 170 MPH and then some didn't do it for you?

 

[95GSX19]

The stock DSM doing 170 MPH and then some didn't do it for you?

I know huh?

 

[KieWhitehouse90]

To answer your questions about what might cause the gas smell -

I found its mostly to do with just generally running so rich, but bad injector seals can do it.
Also, when i changed my fuel pump and lines to braided hoses, the smell has gone away.
Replacing fuel lines isn't too expensive, just a bit tricky if you include the filter too, which i did.

Definitely made a huge difference though.

I used the fuel tank to rail kit from STM.

 

[romeshs]

Just attaching a few pics of the engine bay. if you guys notice anything out of place, please do let me know. wasnt too sure what i should be taking pics of, so i took whatever i could see.

 

[95GSX19]

Check the 02 sensor behind your dipstick, unscrew it from your exhaust manifold and take a picture of it.

everything else looks to be in the right place.

 

[TopGun8818]

Wow! super dusty; looks like the cars from Mad Max
Anyway, I would just perform routine maintenance on the car which is the things that everyone is doing in the reply's above. As dirty and dusty as the engine bay is - I would agree with all of the ^above^ pretty much - I would also recommend you replace your pvc valve and also clean your intercooler as chances are it is all gunked with oil - plus - place a fuel filter between the hose that runs from the valve cover to the intake. Actually just visit the free mods and upgrades section as many of these mods help the car perform and run better.

 

[95tclipser]

You should drop your gas thank & check all the hoses that attaches to it. when I replaced my fuel pump, I decided to drop the fuel tank & thoroughly inspect everything attached to it, good thing I did because the hoses were a little dry rotted & check valve was broken, I replaced all hoses, check valve & all gaskets.

 

[Foreverthuggin0417]

Since your car is completely stock, the only thing I could recommend is staying out of boost. I got my 95 gsT and was really good on gas if I stayed out of boost which is hard to do. After I put my mods on that I got now, I get bad gas mileage. The jc I go to is only 22 miles away and it takes almost 1/3 of a tank to get there and back. So if I were you and you really wanted to save gas I would stay out of boost or get a manual boost controller and a boost gauge and turn your boost down. This should cost no more than $100 bucks. I hope this is of help to you.

 

[007jimmy]

Boost leak test and check for exhaust leaks. Pull the heat shields and look for black soot. Pre turbo exhaust leaks and bad motor mounts caused my gas issues in my auto.

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Now boosting is my only problem

 

[romeshs]

I have been trying to find a set of spark plugs for the car, BPR6EIX is what I've been searching for mainly, but the dealers and shops here doesn't carry it and doesn't have any BPR6E plugs. I've also checked for BPR6EKN and for BPR6EGP. Is there any other plug that will fit and work on it? My issue is if I order it online, I need to pay about 3 times the price of the plugs for shipping.

 

[Clutch450]

NGK BPR7's

 

[romeshs]

Regarding spark plugs, I couldn't find the BPR7's I did find BPR6EIX. Is that an OK plug to put on the car? Thanks guys.

this what my existing plugs look like. all four appear the same. they are NGK BPR6EKN

 

[Cabam]

Mine was my o2 sensor the upper one I was using a half a tank driving 45 mins away once I changed it I nearly see the needle move thank god....

 

[romeshs]

I finally managed to take the O2 sensor off. It was very white... Not black or oily. But I have a feeling that its not the correct one. Weird model number on it...
ND 0065500 9810 12008