wally w

While at Lightening a month ago I noticed a power loss late in the day (similar to camel mode). No codes were present so I added 5 gal. of fuel and it was fine until late in the next session. When I got home I installed a new filter/regulator and added 10 gal. of fuel I had still in the can. At our next event (Summit main) the first two sessions were fine until the third session when the problem returned. I had to leave for personal reasons so I was unable to experment. Both times I noticed that the fuel guage was just below 1/4.
Any ideas. I'm going to The Glen soon and would like to have a full week end.

ajg1915

Your fuel pump is cooled by the fuel. Maybe you should keep it above a 1/4 tank.

AlwaysInBoost

you could be starving the pump for fuel. fuel is where the power comes from, so if the pump isn't able to maintain pressure at the rail, the cylinders will have less fuel to burn which will = less power.

I had something like that happen to me last year. Towards the end of a session @ Thunderbolt I noticed the car wasn't rocketing out of the corners like it usually does. I suspected my plugs were fouled, as it felt like a slight mis-fire, so I pitted in early. As I was driving around the pits doing my cool-down routine I noticed the DIC said "RESERVE FUEL"... Filled up the tank before the next session and all my power was back!

Depending on the track I usually have to fill up after each session. I don't want to go under half a tank now and I'm burning just over half a tank in 25 minutes @ Lightning.

Try keeping the tank full before each session and see if that doesn't cure the problem.

geerookie

I just had a similar thing happen at the NASA Grand Slam @ Pocono this past weekend. It was at the end of the day after about 1 1/2 hours of not stop running. 3 sessions back to back. Then the 4th session we were running the NASCAR oval and about 8 laps in the car just seemed to lose a bunch of power. It would still run but I could only do about 90mph max. After it cooled down it was OK.
I think it is the catalytic converters. They get heat soaked and start to plug up. I was going to pull them this coming winter but now I'm going to do it before Limerock in August.
Just my 2 cents.

wally w

Thanks gee,

After Lightening I had the same thought. Removed the cats (good as new) and the problem still exists. Thinking more, on both days it was "stinking hot". Maybe the fuel was getting to hot to cool the pump.

geerookie

Oh well, if that doesn't fix mine at least it will weigh less

sothpaw2

Curious--was this TrackDaze?

I've run it with just over 1/4 tank indicated and within 10-15 min into the session, it started doing that--I immediately pulled off knowing it might be fuel. I wonder if the engine leans out any as it runs out of fuel? I don't want to find out. That 1 reminder should do the job.

AutobahnRacer

Similar problem last Sunday during a race. I had 1-lap to go, running 2nd Place and RIGHT HANDERS caused me to drop power to about 1/2. Once on the straight, or making a left hander, the power was back. Eventually, all power was gone. I believe the fuel pick up is on the right side, and I just had fuel starvation. Lost two positions, finished 4th, and will NEVER run out of gas again . . .

Han Solo

That's crazy. Maybe these cars need a pump in each tank.

I can run my old single tank/pump Mustang right down to fumes without any power loss. I don't chance it to reserve but I often let it get below 1/4.

RX-Ben

My understanding is that there is a pump for each tank (see below). Maybe the secondary pump is overheating b/c of lack of fuel? I would think this might throw a code, considering how nearly anything electrical throws a code, but can anyone confirm? If no code, maybe the pass side tank is simply too low for it to pump sufficient fuel to the main pump to maintain the req'd pressure (hence the cut at 90mph - can't supply enough gas to go faster).

"There are two fuel tanks, and two fuel pumps. One fuel pump continually pumps gas from the passenger side tank into the driver side tank, and is quiet. The main fuel pump is directly behind the drivers seat, and can be annoying loud, especially on early C5’s."

AU N EGL

Hans you are correct.

Have seen a few world challenge cars with two fuel pumps, one in each tank