Ken89911T

Frustrating problem with right hand sweepers. At 1/4 tank or less, fuel pump can't get enough to keep engine going. Sputters, nearly stalls. This was a problem even before I removed fuel pump to check hoses after FVE's well-documented hose failure. I ended up having to reattach the fuel gauge float device, but I could not identify any problem with the fuel pick-up, and the starvation problem persists. Any one have a solution short of replacement of the whole unit?

Macster

Reads more like a hose has a crack in it than an outright failure. Under high g-forces the crack opens up and there you go.

If I'm right, my WAG would be the crack is down low as it only gets exposed when the fuel level is down.

'course, there is the possibility the fuel level is not calibrated right and the fuel tank actually has less than 1/4 of fuel in it.

Also, even if the fuel level is spot on the money tracking the car with the fuel level at 1/4 tank or below... that could just be the natural limitation of the fuel pickup.

Ken89911T

Couldn't be the hoses. The problem was there before I did a thorough check of hoses over a year ago. There were no problems with the hoses. I was just wondering if anyone else had this problem. Maybe it's just my particular pump that has a problem. It's a pain to remove, so I'm looking for other's experiences to help guide me when I do eventually pull it.

mkk62

I believe it is an inherent problem. The left and right hand sweepers at 1/4 tank I get starvation. Putt putt. One time almost got hit from behind after passing someone who didnt want to be passed as I lost power. Something to do with fuel pickup. Maybe someone more mech inclined can chime in. Are there any 6-gt3's able to run at high g's down to the E on the gauge? If so we have the same prob.

Mike

gvtesse

I have experienced the same problem. I think it is just an inherent problem.

996FLT6

Any particular reason to start off track at 1/4 tank? I always do half tank simply because the warning lite bugs me more. Is street fuel tank 18 gallons? Don't remember. If so 4.5 gallons extra equate to around 31.5 lbs more up front. U can feel that weight up front? Mike

mmuller

I had this exact problem. Just started one day at the track. Would come and go but never with a low tank. People told me the same thing, it was just an known problem. It got worse to the point that you could not go on track and allow it to get below quarter tank. My car is reasonably low miles at about 15k at this point.

I pulled the fuel pump out and carefully inspected the hoses. What I saw where thousands of tiny cracks in the hose and observed a quarter tank of gas was just below these cracks. I bought a new fuel pump which includes the updated hoses and guess what? I can run the car well into reserve without any fuel issue and that was 10 months and 6k track miles ago.

My advice would be to replace the pump assembly and say goodbye to the problem.

Ken89911T

mmuller: thanks for the input. From the other posts, it seems like that just might be the way to go.

Mike: Yeah, I always start the session/race with 1/4 tank. That way, I get the starvation problem right away from lap 1. Actually, I like to finish the race at close to minimum weight, which for me has to be set at 1/4 tank, because below that, I'm not going to be competitive with a starving fuel pump. If I can go lower on the tank, I can have a buffer with other weight items, like a Cool Shirt, etc, that now puts me way over minimum. It's all about weight.

mkk62

Thx too mm. Will have the fuel pump looked at!


Mike

mkk62

Mike flt6. Can you run 1/4 tanks without problems? Wondering if it is g force issue. I'm running kuhmos or slicks and wondering if less sticky tires have less issue. ?

Mike

996FLT6

Wish I could help u. Never had a starvation issue because every session I'm always at half tank. I've had fuel starvation issues on other cars rather take lesser of 2 evils. Mike

mmuller

I can generate pretty high G's in my car and my issue disappeared after I replaced it. It went from starvation at quarter tank to starvation half way through reserve.

mkk62

Chaching. $$$

Will check out the fuel pump


Mike

Macster

Just a side note that running the fuel level down that low even if starvation is not a problem heats up the fuel as it is used to cool the fuel pump. Thus the fuel being fed to the engine is hot though under pressure so vapor locking should not be a problem but the fuel pump runs hotter.

(Even my 03 Turbo has a fuel cooler than is chilled by a line from the A/C compressor when the A/C is on. Porsche must figure if the weather's hot enough for the A/C to be on the fuel needs chillin'.)

Anyhow, while running the tank low and the pump hotter probably won't kill the pump right away it can't help its longevity.

Gasoline weighs around 6lbs per gallon. Hard to imagine a few extra gallons of gasoline having any measurable effect on one's track times.

mmuller

Totally agree. But my wife and I share the car at DE and it sometimes gets triple stinted, spending over an hour on track with only time to belt up between sessions. In these instances, I just cant get enough gas into the car before it goes out, so I have some experience in this by default.