993944S2

F class 911. Fuel cell. All components of cell are tested good. Foam etc. Car runs perfectly. When we get to about 7 gal, we start to get a miss in high G corners. I know. Sounds like a pick up problem, but we have done all kinds of things to ensure the pick up is doing its job. We run a AIM MXL. We have the typical sensors active. TPS, EGT, fuel pressure, fuel level, Lambda.

I'm new at the data analysis. If I can identify a specific corner that miss happens, what data can I look at to try and "see" the miss? For example, I assume if we go lean on the miss the EGT will rise.

Any suggestions greatly appreciated.. If you need more information please ask. I don't have the actual data files with me until Friday. Thank you very much.

pmiranda

I would start with fuel pressure.

ProCoach

Think about the timing of the event. Lateral g's would come up first, followed by a fuel pressure drop (a significant one and extended, too), then the RPM would level out with the misfire. But all three would need to occur in order to blame it on that.

Matt Romanowski

I'll post some screen shots later, but you will want to do X-Y plots of things like fuel pressure vs lateral f, lambda vs lateral g, etc. You can also use the GPS plots with measures on them to see where they are changing.

ProCoach

Nice having Lamda and EGT's, that would point immediately to a lean condition. Something as simple as aspirating air at a fuel system connection or in the cell. I love the GPS color-with-value maps because you can look at the issue from several different ways, for validation.

Plavan

I had the same problem on my 911 years ago. Once the tank got to a certain level, or a certain time frame of being on track, it would start missing. After tons of troubleshooting, I finally just opened the fuel cell. My Fuel Safe cell had the rubber flapper disintegrate (brand new cell). I had to call them to have them let me know of the recall????... They had a "Quiet" Recall on the rubber flappers.

Anyway, after a certain amount of time and lower fuel loads, the pickup would get covered by the disintegrated rubber flapper. My car would start missing and losing power.

I got a rebuild kit and a brand new (Better) Pro model Fuel Safe cell free of charge after I let Fuel Safe have it...