Phokaioglaukos

The last couple of track outings I have had fuel starvation stumbling when my fuel gauge gets to ¼ or so. The symptoms are that in high speed turns the engine will not rev to more than about 6,000 rpm, but not with the stuttering when actually hitting the rev limiter. The engine will not die, but it won't accelerate. If I stop, add fuel and go right back out on the track the symptoms go away.

Any ideas?

va122

Woah Chris. The 6k thing is the limp home mode i'll bet. Just bring it into the dealer. Could be as easy as your fuel gage being off. Do you get the low fuel warning?

Phokaioglaukos

No low fuel warning.

Holger B

Clogged fuel filter?

Phokaioglaukos

I thought about a fule filter--not changed in 4 years and about 40,000 miles, but that affects the flow of fuel at all levels of fuel.

Holger B

I thought the same thing too, but seems like it's worth replacing. Any debris in the tank will be more concentrated at low fuel levels, then throw in the cornering g-forces and...

Victor may be right about it being in "safe" mode, but I'd think you'd get some type of warning for that.

Don't know, just guessing.

Camber

Could it simply be centrifugal force pulling the fuel to one side of the tank and away from the fuel pump pick up? I have never driven below a quarter tank on the track for fear of fuel starvation and having the engine run lean.

What direction are you turning, i.e. does this only happen turning left or only turning right or both?

It might also be interesting to see how much fuel it will accept when you refill. Is the volume more like 3/4 of the tank's volume or all of the tank's volume?

Assuming you drive on the street, what happens when you go below 1/4 tank? What if you then take a freeway ramp at some speed?

Just some thoughts.

Phokaioglaukos

Good thought, Jim. Last year I ran the car to absolute empty (had to be towed in) on the same track and there was no stumble before it ran dry. After refuleing it was fine then, too.

It seem sto happen on turns of either direction, but more evident on right turns because of the track. I could be wrong about this, though.

Good thought on measuring how much fuel can be added--that would tell whether it's a pickup problem or a fuel gauge malfunction.

No issues on the street, but I cannot get the same Gs either.