Hoping I could get some advice. I have been having an issue with fuel pressure / fuel pickup at about 30 minutes into a race/session. At that point I have a loss of power and loss of fuel pressure (as indicated on my stack) while going through right turns (ones usually preceeded by a hard left turn). It's very consistant at that point on the track where it first begins to occur then begins to get worse, occuring at other corners, as the session continues. I ran a 45 minute race and the 90 minute enduro (with pit stop) at VIR last weekend and needed to nurse the car home each time. At the end of each session I can pump another 2 1/2 gallons in the garage, which indicates to me that I have at least 4 gallons in the cell when this starts happening. I confirmed that the cell will take nearly 8 gallons of fuel from empty. Inspection of the cell (10 years old), foam, vent, returns line, and pick lines all look fine. I don't have the surge box, maybe this will solve the issue?

Thanks,

Bill

first guess is the lack of the surge box - when you are turning right the pickup is not getting constant fuel, and in a FI car this means no FP>>power.

^+1
No surge box in these cars = fuel frustration from everything I've ever seen or heard. That would absolutely be the first thing I'd do to address the problem. Ask your local CSR for some recommendations when you put it in so you don't stub your toe on well trodden ground.

Knock on wood, but I haven`t used a surge box since the inception of the SRF and have never had a pickup problem. Not saying don`t put one in, just my experience.

make sure the proper fuel lines are connected to the proper fittings on the fuel cell. Heard of one instance where the two lines were reversed and caused the exact problem you are experiencing. good luck.

I am having the same problem, but it happens 10 minutes into a session on a full tank. Only left-right combos do it. I can pull hard RH g's with no drop-out as long as I am coming off a straight. I have a surge box.

Proper lines... proper fittings? You mean not trying to draw fuel out of the return?

Duhhh wrote:Proper lines... proper fittings? You mean not trying to draw fuel out of the return?

Or even worse, the vent...

What happens if you try to just pump the cell dry without driving the car?
We've had problems with a couple cars in the past that have been caused by several different (and sometimes multiple) things...
1) make sure the cell is getting full (which Bill already did) if not, it could be an improperly mounted vent line.
2) Make sure lines are connected to the proper fittings. I have seen a car with a fourth capped fitting that didn't have anything connected on the inside.
3) Make sure surge box is properly installed (fittings in the right direction, positioned properly in bladder and pickup line connected (my speculation is this is what Bill's problem is). There are instructions in the assembly manual, we have had problems similar to Bill's and found the surge box mounted 90 degrees off and up against the step in the cell...
4) Make sure the fittings haven't gotten twisted while installing lines on the outside. This can move or crimp the lines inside or maybe even loosen them so they leak.

Best bet is to be really systematic about installing the cell (once getting a surge box). We wasted a lot of time jacking the car up, taking the cover off and trying things. Or taking everything apart at the shop, changing something, putting it all back together and taking it to the track and trying it. Now if we take one out, we at least partially) fill it and pump it dry with the seat and bulkhead out. I've also been able to position the vent line so you can feel it through the bladder to make sure it is in the right place.

The first time I had the problem, I wasted a lot of time trying to find quick fixes, when I finally got the nerve to take the cell out, I fixed it right way. Of course the next time we had one, we had the cell out and in three times before fixing it...

Thanks. I wonder if the pick up line is moving around? Are the foam blocks expected to hold the pick up in the proper place? I suppose the one advantage of teh surge box is to secure the pickup and return lines in the proper place. One other thing that usually happens is that when I add fuel and insert the tie wrap into the vent valve fuel usually squirts out. I assume this is typical?

Bill

I had the same problem years ago. It was the pick up hose at the baulk head fitting inside the cell, if theres no hose clamp on it , it will suck air when the fuel level gets down to that point, hose loosens with age