Reference 1997 E36 M3 Track Car

This car has the dual pump setup but at VIR this last weekend it was acting as if it was fuel starved when the tank got below 1/2. This has never happened before. I checked the connections on both pumps and they are both running. The passenger side (54,000 mile) is a lot noisier than the driver side that was added some time ago. James Clay was in the car with me and it felt like fuel starvation to hiim as well.

The fuel filter was replaced 15,000 mile ago.

Do these pumps fall off in efficiency as they get louder or older? I noticed that the driver side pump starts whining when the fuel gets low, but it goes away when you put in gas. the passenger side pump is noisy all the time.

Thanks in Advance,

Chris

Depending on how you've configured the pumps, the pickups and the plumbing and the electical, there are a variety of problems you could be facing.

I think I've had them all happen to me, that seems to be my poor execution, or planning, or luck.

If the pumps on one fuse, be aware you may draw more than that fuse is capable of.

If you have the pumps "T" ed together to one output, be aware that creates a lot of back pressure, and in fact, it could cause a hose to fall off between the pump and the top flange of the pump set up.

Hoses that are internally routed can fall off, or come out of their proper position. Depending on what part of the internal siphon system you've retained, or if you've set up one pump to pump to the contralateral side first, they may have come of position.

Thats all that comes to mind for me. I've found that having a fuel pressure guage (finally) makes debugging the system MUCH easier, you can simpy fill the tank, and clamp off the output of one, and test the other and vice versa.

Alex.