My car has a prob, i think it might be a bad gas sensor but i wanted to be sure. The last mod i have put on is my afc-II and that is untuned (correction = 0%). I drove 50 miles and it says i ate up 1/4 tank of gas. I checked the fuel rail with the car on and it dosen't leak, i left the car in one stop and did not see any gas spill out. I am changing my spark plugs, and air filter soon (although this is extremly unrelated i beleive). What could it be?

I am was planning on upgrading my fuel pump, i doubt it, but would a new sensor come w/ a new pump?

Any info is appreciated.

alot of good suggestions there look at injendsm's (o2 sensor maybe)



http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=65547&mesg_id=65547&page=

you drive 50 miles and the gas gauge says you used 1/4 tank.........am i understanding correct? When you say gas sensor you are referring to the float assy in the tank right?

Couple things to chk.....how does the car run and feel? Remove the gauge sensor in the tank make sure the float hasnt come loose or that it hasnt deteriorated. You will see any obvious damage. you can even turn the car on with the float assy connected and move the float to see the gauge is semi accurate.

next if you have a datalogger you can let the car sit all night, hook up your datalogger or scanner and check the 2 o2 sensor counts. They should be very close, if not suspect a bad front o2. the o2 can go bad and not trip a CEL, its quite common.

If you car is running rough or hesitates then do your tune up and replace the O2.

A new pump is just that pump only no float. If the float is bad you can get one for 10.00 used people on the board have extras, myself included.

Terry



96 Eagle talon ESI
Greddy header - Greddy exhaust

97 Eclipse
Star Stage II - Boost/oil/EGT gauges - 3" custom DP/Apexi N1 3" exhaust - SFMU/return line - Apexi SAFC - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks

Waiting to be installed: HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

i would only check the float if the gas mileage is about the same. if its bad (use mileage and gal when you fill up) the just replace the O2.


96 Eagle talon ESI
Greddy header - Greddy exhaust

97 Eclipse
Star Stage II - Boost/oil/EGT gauges - 3" custom DP/Apexi N1 3" exhaust - SFMU/return line - Apexi SAFC - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks

Waiting to be installed: HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

I will do the tune up first, i will change those little things that i mentioned although i extremly doubt they will make a diff.

How do you remove the gauge sensor in the tank so i can make sure the float hasnt come loose or that it didnt break?

Also where can i get one? You mentioned you had extras hehe.

EDIT: the car does not run rough at all, performs well.

i have the same problem...the gas gauge like randomly goes down then goes back up lol..and if i turn sometimes i hear somethin rollin around...what that be my float?

I am preventing your hi jack = )~ . Thats is probably your float....


Mine doesnt go up btw. I was looking at o2 sensors if that could be it, i see they say before the catalyst...Well I have a Header, and headerback exhaust..the car has an o2 sim in the exhaust from the previous owner (he had it on stock piping and I had the headerback exhaust made it was put in as well). Well i have the 1 o2 on the header will that still fit even though it says before catalyst?

PS How i check the float?

yes could be the float of the sendignunit in the tank going bad. If you look at one they are very basic construction. To access yours pop your back seat bottom out and remove the inspection plate in the middle. That is where the fueld sending unit is located (float assy). If yours is bad i have one you can have for 15.00 shipped or pushin420a probably has a crapload of them from all the cars he has parted out.

After you drie 50 miles go fill your tank up see how many gallons it takes. Devide to find mileage....mi/gal = miles per gallon. This will tell you right away if your actually using that much gas.

After 50mi it should only take appx 2gal to top off the tank. You havent installed guage overlays recently have you?

Terry

96 Eagle talon ESI
Greddy header - Greddy exhaust

97 Eclipse
Star Stage II - Boost/oil/EGT gauges - 3" custom DP/Apexi N1 3" exhaust - SFMU/return line - Apexi SAFC - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks

Waiting to be installed: HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

I just filled up, it said i hade 1/4 tank and it filled up 9 gallons so i think the float assy is not broken.

What do you mean gauge overlays?

yea sorry didnt mean to highjack at all..forgot to put that

Mods: E-bay Intake, Vibrant Muffler, J Woodleys Ground Wire Kit,F&R Upper Strut Bars

Future Mods: Custom 2.5 inch piping, AFX UDP, and a real CAI :)

*Selling an OBX High Flow Cat 45$ shipped*:-(

Originally posted by reeveso
yea sorry didnt mean to highjack at all..forgot to put that Mods: E-bay Intake, Vibrant Muffler, J Woodleys Ground Wire Kit,F&R Upper Strut Bars Future Mods: Custom 2.5 inch piping, AFX UDP, and a real CAI :) *Selling an OBX High Flow Cat 45$ shipped*:-(

i was just messing with u hehe.

So about those gauge overlays?

Gauge overlays...indiglo gauges...you have to slip them over the needles and if you distubrb the fuel needle it can read inaccurate.

Terry

No i did not install any guage overlays. So far here is where i am at.

-I saw no leakage at the fuel rail when the car was on, and i only smelled gas coming out of the exhaust after it idled for a little while (richness?)
-I doubt the o2 sensor is bad b/c i would notice poor performance
-It said i had a 1/4 tank, and i filled up 9 gallons-ish, so i dont think that the float assembly is broken.

Could it be that im just running that rich? If so I need a tune asap lol.

Yes you are running that rich if it smells like gas out the rear of the car. It sounds to me like it's the O2 sensor. There is a thread going on them already so check there for more info...