Fuel pump?

Hi again everybody,

I'm really hoping I don't have to replace my fuel pump. Please assure me otherwise :(

My 2000 sunfire will only start when it has a mostly-full gas tank. If it starts to get low, the engine will start, then promptly die. After a few tries, it will stay running (unless I'm under 1/4 tank, in which case it just keeps dying over and over again and will not start at all, which just happened when I tried to leave this morning. Put in 5 gallons I had in the garage, and it started, so I took it and filled up the tank completely.)

Is this a sign of a bad fuel pump? I've tried to figure it out via internet research, but can't find anything on why having more fuel in my tank would allow it to start better. That's why I'm wondering if it's not the fuel pump itself, but maybe something not keeping the fuel in the lines? I'm not familiar with how the fuel system is set up, but I'd imagine a bum fuel pump would result in the car not working no matter how much gas you've got. But I'm probably wrong. *sigh* Fuel pumps are expensive.

Any ideas? I appreciate it!!

- Colleen

A bad fuel pump is a possibility but I don't think that is the real problem. It appears that the fuel pump is losing suction when the tank is low. I would pull the fuel pump and examine the pickup end of the pump and see if it is clear of debris. There is a sock on the fuel pick-up that will keep large particles out of the delicated pump. They are inexpensive and easy to replace once you get the pump out. I would also check the fuel pressure regulator located on the engine. It may not be maintaining proper pressure and allowing the car to stall even though the pump is working. Check the regulator first and then tackle the fuel pump if that doesn't fix the problem. Good Luck!

Wow, that was a quick response, thank you so much! :)

Could it possibly be the fuel filter or maybe a problem with the check valve? I just got this car used 6 mo. ago, it's got 85k miles on it, not sure if the fuel filter has been/needs to be changed... could that cause the problems I'm having?

It certainly could be a blocked fuel filter. Change it and see if the car runs better. Do this first as it is the cheapest and easiest part to change.

Ok, update on the status of my poor fuel-starved car:

I took it to my mechanic and he replaced the fuel filter and cleaned the fuel injectors ($160, ow.) Then he went to park it for me... and it died. So apparently, that didn't fix the problem.

So he's going to have to take off and check out the stuff in the fuel tank, which is a $400+ job (ow ow ow... I'm a poor college student, I don't HAVE that.) He's thinking it might be a short? o.O I told my mom (who's dealing with all this since I'm away at school during the week) to have him check the sock on the fuel pump like GTP Dad suggested. I'm just really hoping i won't need a fuel pump, because I absolutely positively can't afford that. Geez, I wish cars weren't so expensive to fix. :( Makes me inspired to become a mechanic. lol

ok just to let you know on your fuel pump....if it goes out as far as electronically the relay will kick on either the 85 or 87 circut to keep fuel flowing.if it wasnt your injectors i would get a pressure test done and look for any deteriorating lines in the system. possibly an EGR valve could cause you car to stall just the same....if you dont get this problem fixed and they are sensors it could ruin other ones to. get an OBD2 scanner....well worth the money ..not to mention you will know what a mechanic is going to have to fix and lessons your chance of him lying to you

Wow! Someone is experiencing the same problem with their sunfire?
I own a 2000 Sunfire 2.2 liter, and I believe I must have filled it with
some bad fuel. This has been very common recently around here in Houston. Had a recent news story where 11 cars didnt get out of the gas station parking lot.
Car ran fine before that fill up. Took it to the store, got some
food, came back out to the car, and no start. Finally after cranking
for a while, I got it to start and stumbled home. Shut it off at home,
and would not restart. Changed the fuel filter and added some
Chevron Techron fuel system cleaner. I drove it around for a while to
burn off the gas and filled it back up with super unleaded. It has
been about a month now, and yet, if I let the fuel level get below
a quarter tank, it will be very difficult to start, if at all. And this happens
when you get out to go somewhere, park, and then come back to the car to try to go home, No start. Yay! I have had to get my wife to bring
me super unleaded gas in a 3 gallon can so I can add it to my tank, and
then it starts like a champ with no problem. It has recently passed fuel
emission testing during inspection, so I dont know.
Any results from sgvampyr's post #155? Can I siphon everything out of the tank and refill with clean fuel? Maybe replace fuel filter again? Fuel pump
always sounds like it initializes when I turn the key in the ignition. You know, that three second whirring noise you get? Engine turns over, but no start. Getting spark. No fuel smell. Injectors are clicking when its running (stethoscope). Any ideas would be greatly appreciated!
---

I took the car to my mechanic, and it cost a total of $550 to replace the fuel pump (they also cleaned the injectors and flushed my fuel system.) :\ Apparently the pump wasn't totally dead, but was "dying", and would have eventually totally crapped out on me at some point. I was hoping that it wasn't the problem too, because I could hear the pump starting when I turned the ignition, too, just like you. If you have a friend who knows cars and can change fuel pumps, or if you can yourself (without having to go to an expensive mechanic - I only went because I didn't know WHAT the problem was; now that I know, it kind of sucks cuz I have friends who'd have replaced it for free) check it out and see if it's clogged or something. My mechanic charged $175 just for labor to take off/get into my gas tank, then the additonal cost of the pump itself made the fix kind of expensive. :\ But yeah, good chance it's the pump, sad to say :(
I didn't have to put super grade gas in mine to get it started, as long as the tank was above 1/4, it would start after a couple cranks of the ignition. Or rather, it started, but then died immediately, and eventually STAYED started. Above 1/2 tank, it was totally fine. So don't waste the extra $$ on high-octane if you don't need to.

Rayzur9, have you tried any fuel line antifreeze in the tank. It sounds like you may have a good deal of water in the bottom of the tank that is causing your problem. I don't know for sure but that is what it sounds like to me. If that doesn't solve the problem and you have to change fuel pumps watch out for dealers as their prices are out of this world. Get a manual and change it yourself if it needs changed.