Help the poor college kid

AK Maniak · Feb 25, 2011

Okay guys I need some help with my GSX. When i got the car it stuttered under boost so i put in new spark plugs and it went away completely. Its been about 3 months since then but now the car gets about 9mpg while driving normally and only hitting boost occasionally. When i start the car i can smell gas quite strongly and when i'm in boost the smell comes right back. Then last night when i was driving I hit boost and the car started to for lack of a better term, shake. Felt like it was bucking but they were very very small bucks and in rapid succession.

I have done some searching and I have a few ideas on where to start but my question is what would you suggest doing first. I am very broke as i am in college but I need my car to be somewhat reliable. I'm hoping i'll get lucky and it'll be an easy fix but i doubt it. So for someone who has little to no money what would you suggest doing first?

Silver99OZ · Feb 25, 2011

Are you throwing any codes? My friend bought a gsx a few months back that was running a little rough and getting bad gas mileage, ended up needing a new O2 sensor. Ran perfectly after replacing it, and gas mileage went way up.

gho5tone · Feb 25, 2011

Check for codes and like the guy above says it could be a front o2 sensor going out.

AK Maniak · Feb 25, 2011

I got a code a while back and went to autozone and it said fuel pressure or fuel solenoid but I was told that it might due that because of the elevation here (7500ft). Any ways i reset the codes and it never came back and this was about 2 months ago.
Although now that you mention o2 sensor this might be relevant. shortly after purchasing the car one of the wires coming off the alternator rubbed against my o2 sensor and blew a few fuses, could that have done anything to the o2 sensor itself?

NeMiZiS · Feb 25, 2011

What kind of gas do you run? I hope not holiday gas.
Since it went away entirely, when you changed the spark plugs.
Have you pulled them back out, to see what they look like now?

If you wanted a reliable car, you should have kept your 420A.

AK Maniak · Feb 25, 2011

I fill up at chevron pretty much everytime and I have pulled the plugs and they looked fine. A bit white so i'm assuming i'm running somewhat lean

907gs-t · Feb 25, 2011

I would start with a BLT.

EclipseGS-92 · Feb 25, 2011

the bucking sensation very strong and prevents acceleration past a certain vacuum?

My 92 gsx did the same thing when it cooked the turbo seal. was popping black smoke when it did it too.

fran_drivertsi · Feb 25, 2011

If it smells like gas... Wouldn't it make sense to go under the hood and check for possible gas leaks? Fuel feed/return line, fuel rail, injectors.. Check your gas tank in the back. Find a source of the leak before your shit becomes nothing but a crisp.

KyDSM · Feb 25, 2011

MAF or O2 sensor. Check them!

AK Maniak · Feb 25, 2011

fran_drivertsi said:
If it smells like gas... Wouldn't it make sense to go under the hood and check for possible gas leaks? Fuel feed/return line, fuel rail, injectors.. Check your gas tank in the back. Find a source of the leak before your shit becomes nothing but a crisp.

I have looked a bit but i never found anything. Wasn't the most thorough search though so i'll probably go do that now.

KyDSM said:
MAF or O2 sensor. Check them!

Is there anyway to test the MAF and o2 sensor other than just replacing them?

AlaskanDsm · Feb 25, 2011

Borrow one haha.

AK Maniak · Feb 25, 2011

NeMiZiS said:
If you wanted a reliable car, you should have kept your 420A.

ha ya i was planning on it but then i found out how much it was gonna cost to get it shipped down to AZ

AlaskanDsm said:
Borrow one haha.

i have the only DSM around, would an evo 8 or 9 o2 sensor work because there are quite a few of those around

AlaskanDsm · Feb 25, 2011

You need a 2G sensor? I might just have someone who might be able to sell you one dirt cheap. I will PM you details.

AK Maniak · Feb 25, 2011

AlaskanDsm said:
You need a 2G sensor? I might just have someone who might be able to sell you one dirt cheap. I will PM you details.

Okay thanks

KyDSM · Feb 25, 2011

If you have a multimeter, wire and pins you could test the volts and ohms at each pin. But I'm not to positive on the specs. Easiest way it to just slap in another one. They are cheap.

AK Maniak · Feb 25, 2011

I grabbed some MAF cleaner and i'm getting an o2 sensor within the next few days. Afterwards i'll report back with my results, wish me luck!

etay89 · Feb 25, 2011

white spark plugs indicate that your engine runs a bit too hot and that you may be running lean and have a leak in the vacuum lines. so here's what I would do asap: get some ngk bpr7es's (like $10 on ebay for 4), gap them right, flush the radiator ($12 for the coolant).

as for the poor fuel mileage, check the front o2 sensor (bosch 13425 is a direct fit...around $50-70) and maf just like everyone else said.

also, though it's not for tuning purposes, just an indicator, see if you can get a narrowband air/fuel ratio gauge ($20-40 used or new).

Usatuff · Feb 25, 2011

Have you or the previous owner did a fuel pump? I had the same problems... found out my fuel hanger was held on with painters tape and had no pressure in the tank

GsXdSmKingGsX · Feb 25, 2011

AK Maniak said:
I fill up at chevron pretty much everytime and I have pulled the plugs and they looked fine. A bit white so i'm assuming i'm running somewhat lean

Pretty sure he meant what grade of gas are you using.

EclipticalGS · Feb 25, 2011

I had the same problem. If you can still build boost, you smell fuel at start-up/idle, and your mpg is horrible. Your car isn't going into closed loop. A simple log of any sort would show why.

Either your 02 sensor is dead (mine was and didn't throw any codes), your coolant temp sensor is bad, or your TPS is set too high, these will all play a role.

2 years ago when I had this problem, I replaced the coolant temp sensor..No change. Replaced the MAF sensor..No change. Clean my IAC, and reset my TPS/Biss..No change.

Pulled one log at idle to show my front 02 voltage at full warm up .020 volts.

One of these is it. Im betting o2 sensor.

Btw. Boost leaks at idle draw in un-metered air resulting in a lean idle condition. Boost leaks during boost result in a loss of metered air resulting in rich trim.

rush2252 · Feb 26, 2011

I would consider checking the fuel pressure regulator. Would best explain the intense raw fuel smell.

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Help the poor college kid

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