I've got a 2000 GMC Jimmy 4dr 2wd with 151k miles on it. When i have less than 1/4 tank of fuel it generally takes a couple extra crank rotations to start and/or stumbles for the first second before it gets up and starts idling. this is exacerbated if i am parked even at a slight incline downhill (wanting to roll foward). enough of an incine and the car wont start at all.

with the same less than 1/4 tank of fuel, the car will also stall out if i slow down and take a right hand turn at a "normal" pace, or if i just get on the brakes hard for 2-3 seconds (fuel rushing foward in the tank away from the pump in the rear of the tank). once i finish the turn and get pointed back straight and am still rolling from my momentum, i can pop it in neutral (automatic trans) and turn the key and it fires right back up with the normal hesitation i get from low fuel starting....... and off i go, usually to the nearest gas station. i've also noticed lately that even while cruising down the road at any speed 20-65 mph, if the fuel level is closer to 1/8 tank (but still not low enough to turn on the low fuel light) the motor will start to drop out if the road i'm on has even a little bit of downhill to it. it hasnt stalled from this but its gotten close.

generally i havent been able to get to my low fuel light being on because i've started stalling out too much. i have unscientifically verified that the fuel gage is still accurate because my tank has only been taking 15-16 gallons of fuel when the stalling problems have started. before the problem started i could usually use about 16 to 16.5 gals before the low fuel light would come on, and i could drive until the gas gage went right down to the E line and i'd put 17.5 gals of fuel in it and i'd never stall or even hesitate. my owners manual says the tank is 18 gals. so i'm definitely thinking for some reason the fuel pump is not picking up all the fuel in the tank.

now.... what i've checked out and changed......

the fuel pressure regulator was replaced less than 1 year ago. i've changed fuel filters recently. i also changed the fuel pump strainer screen on the bottom of the fuel pump (see attached drawing item#4 and photographs on 1st reply.... original screen is the clogged up black one, and the new screen is the white one). when i changed the strainer screen i also completely poured out the tank and wiped up the little bit of dirt/grit that was in it to make sure it wasnt clogging the strainer. there actually wasnt much but i cleaned it up anyways. this strainer screen change seemed to help the problem a little bit but its still not good.

with the key on, engine off, fuel pressure is 61-62, turning the engine on knocks it down to 53-54 or so. with the car on a downhill incline and low fuel to where the engine wont start, the fuel pressure with key on, engine off is in the mid 30's jumping around...... like it is not picking up enough/any fuel.

i'm trying not to buy a new fuel pump because the one in it still pumps good pressure...... its just not picking up the fuel (yeah i know its got 150k miles on it and its gotta go sometime soon.....). its like the springs that keep the pump pushed down low in the tank have given up some and the pump/strainer screen doesnt sit on the bottom of the tank.

anyone else ever have any problems like this?

old (black) and new (white) fuel pump strainer screens

new strainer screen installed on fuel pump intake

side view of strainer screen installed on pump intake.

 

bump one time to see if anyone else might have an answer?

 

dont run the tank down under a 1/4. the fuel pump really doesnt like that and it is a good way to burn one up.

 

Just how steep is the slope you are sitting on when it doesn't start or when it falters??

You really need to keep the tank level up if you are driving on moderate to steep slopes.

 

not a very steep slope at all. i understand that somewhat of a steep slope will make the fuel run away from the pickup, but without the low fuel light even on on level ground driving i can get on the brakes normally and if i just stay on the brakes it will die. if i catch it in time and let off the brake it will pick back up.

 

I replaced a fuel pump in a 2000 s 10 just a week ago.
the small line that goes from the top of the pump to the bottom of the
module cup has fallen off.
it ran great until the fuel got low and would run out at 1/4 tank.
consider this-
this tube feed a venturi which sucks fuel from the main part of the tank and keeps the "cup" full. the return is exactly over the cup and it dumps the unused fuel back to the cup. if the hose has come off then at low fuel levels the fuel sloshes to the f/r or sides starving the pump.
its easier to remove the bed on a 2000 p/u than to drop the tank!
I have done it several times in one day.
Just a note. the ground for the pump is on the ds rear frame rail.
the pump will not come on if you don't reconnect the ground with the bed off the truck. I learned this at the first time i took the bed off!