Gas and start up problems

[cease1981]

Hello I have a 2005 pontiac grand prix gtp with under 120000 miles and I notice when I Drive the gas gage never moves no matter how long I Drive it the only time it moves is when the car is in Park I only use 93 octane gas and on a full tank of gas I only get 170 lousy miles before the gas light comes on, and in the morning my car will only start on the second try not the first try that just started happening if anyone has any insight that would help me it would be greatly appreciated

[BillBoost37]

First off.. it sounds like your fuel level sender may be bad.
Secondly if you live in Philly and don't see any highway, your mileage will suck. You don't mention driving type/style, so I'll assume you sit at stoplights in the city all day. 170 to the tank isn't so bad, especially since you are filling up pretty often since the gauge isn't working.
Third Try cleaning the maf sensor. If not that.. when was the last tune up etc?

[cease1981]

thanks for the response I only had the car for about 4 weeks I change the supercharger oil which was completely dark you could not even see through it I change the air filter which was completely dirty and full of leaves, I'm guessing everything else is completely original to the car including the wires and spark plugs I will give that a try I've already cleaned up the mass airflow sensor with the cleaner I also tried to buy a fuel filter but the guy at the auto parts store told me it was a in tank filter I don't know if that means its not changeable and yes my driving is pretty much stop and go so I guess that can be the reason why I'm mileage isn't so good

[SlowNA06]

Yeah, your fuel filter gets changed when your fuel pump goes bad. Don't sweat it.
Definitely do plugs and wires.
Also, clean the throttlebody plate - it's bound to be gunked up inside.

[Chadgervais]

My car will only start on the second try as well. There is a valve in the fuel line that is supposed to keep the pump primed and the line pressurized. When the valve fails, it allows the fuel to return to the tank and the pump to lose its prime. Turning the key to ON once or twice before starting primes the pump and it will fire right up.

Mine has been doing it for a year now, mechanic says is nothing more than a nuisance. Be careful not to keep cranking on it though, it can wear out the starter.

And your gas mileage is not abnormal for all city driving. My sending unit is bad, any my low fuel light will come on with 9 gallons left. Keep track of how much it takes to fill up, and remember, our tanks are 17 gallons. If you fill up after 170 miles and have burned 9 gallons, youre doing ok. Even with a supercharger, 93 is unnecessary, use 89 if you feel you need it.

[SlowNA06]

In this house, GTPs get premium and they're thankful for it. And they don't get to wear makeup until they're sixteen, do you hear me?

[Chadgervais]

got it, good luck finding 93 in Maine though. Most places, especially north only have 91 (even if the tag says 93).

[SlowNA06]

91 is premium. 93 is super. Or something.

[Chadgervais]

Back in the day we had 93. I manage a Sunoco station. The only way we can get 93 now is to buy 10,000 gallons at a time. The pipeline for our area has 87 and 91 only. In Massachusetts, many stations especially Sunoco have Ultra 94, and full blending pumps offering 87,88,89,90,91,92,93, and 94. We get 87 and 91 and blend it 50/50 to make 89.\\ Funny thing is, when we got new pumps this year, they sent us the button sticker kit which included an 86 sticker. I wasn't aware 86 was available anywhere, or that it could be run in todays engines.

[SlowNA06]

What would you... lawnmowers and weed whackers?

[cease1981]

My car will only start on the second try as well. There is a valve in the fuel line that is supposed to keep the pump primed and the line pressurized. When the valve fails, it allows the fuel to return to the tank and the pump to lose its prime. Turning the key to ON once or twice before starting primes the pump and it will fire right up.

Mine has been doing it for a year now, mechanic says is nothing more than a nuisance. Be careful not to keep cranking on it though, it can wear out the starter.

And your gas mileage is not abnormal for all city driving. My sending unit is bad, any my low fuel light will come on with 9 gallons left. Keep track of how much it takes to fill up, and remember, our tanks are 17 gallons. If you fill up after 170 miles and have burned 9 gallons, youre doing ok. Even with a supercharger, 93 is unnecessary, use 89 if you feel you need it.

Cool, i guess the owners Manuel got me nervous to use any octane less than 91 because the books says 91 or higher anything less you could get knocking the only reason i use 93 is because BP jumps straight to 93 and i like the way my car accelerate on that gas vs other gas stations

[cease1981]

Yeah, your fuel filter gets changed when your fuel pump goes bad. Don't sweat it.
Definitely do plugs and wires.
Also, clean the throttlebody plate - it's bound to be gunked up inside.

Thanks, when it come to fuel pumps is their a cretin brand i should get over others pep boys have one for $380 and amazon have fuel pumps under $200 i was kind of disappointed when i did not see the fuel pump access panel in the trunk like in my last Pontiac meaning i think they might have to drop the tank to access the pump