fuel cell with fuelab pump cavitation issue

[beems240sx]

i have a 10 gallon rci fuel cell running the Fuelab phantom pump. i already burned one up and just got it rebuilt and am still having issues. i have it set up like this. fuel filter, pump, filter, rail, regulator, return. both feed and return are on the bottom of the fuel cell. all -8an lines. i run the pump on reduced duty cycle which is 40%. also have the breather running outside the car. the pump randomly does the weeeEEEEeeeeeEEEEEEeee sound that it did before it seized up. i can shut the pump off while driving and it will go away for 5-10 minutes and come right back. pump itself was not super hot or fuel itself either. im at a total loss why its doing this. ideas?

pics

before i set up the breather line

http://i129.photobucket.com/albums/p204/beemsmx6/image-1_zps5fb10b76.jpg (http://s129.photobucket.com/user/beemsmx6/media/image-1_zps5fb10b76.jpg.html)

http://i129.photobucket.com/albums/p204/beemsmx6/image-1_zps00c67306.jpg (http://s129.photobucket.com/user/beemsmx6/media/image-1_zps00c67306.jpg.html)

http://i129.photobucket.com/albums/p204/beemsmx6/image-1_zps408efbdd.jpg (http://s129.photobucket.com/user/beemsmx6/media/image-1_zps408efbdd.jpg.html)

about ready to switch to a bosch 044 and see if that gives me problems too. just want to drive my car and not worry about it anymore!

[fullthrottle]

You are burning up pumps because your return is on the bottom of the tank. It needs to return to the top. I did the same thing on my first fuel setup.

[beems240sx]

Inncorect sir

Fuelab Tech Tips: Return Line Plumbing - YouTube (http://youtu.be/dP6Pogm6Ts0)

[[email protected]]

If you have two pumps that are having the same issue, there's an install problem somewhere. One pump having issues could certainly be a fluke/failure on the pump side. All pumps are ran through an automated test before leaving our facility- high speed and low speed, free flow up to 100psi (a little lower on the 40401 since it's not meant to be ran that high). Test stand demo- Introduction to the Fuelab Automated Test Stand - YouTube (http://www.youtube.com/watch?v=eAZHIwe3k3c)

Return on the bottom will not cause any problems. That's actually better than an overhead splash return because the pump can ingest air. The absolute perfect way is a dip tube coming in from the top and entering below the fuel level- but the way he has it is just fine. See the quick demo video we did on return line plumbing- Fuelab Tech Tips: Return Line Plumbing - YouTube (http://www.youtube.com/watch?v=dP6Pogm6Ts0)

What model pump do you have? Anything above a 40401 should have a -10 feed going to the inlet side of the pump. You are welcome to step down on the outlet side, but the inlet should be a -10. Personally, I would have a -10 feed on the 40401 as well, but it's not *required*. Also, are you sure you have the pumps in the correct order? We've seen many instances of cavitation damage in the pumps from the fine filter being before the pump and the pre-filter being after the pump. The pumps can push fuel with no problem, but they don't like to pull fuel (same with any pump, not just ours). If the filters are in the correct order, have you opened up the pre-filter to inspect the element for damage or debris?

Also, is there any baffling in the tank? Foam? How full is the fuel level? How is the breather set up and what size is it?

*Edit*

Just noticed you already linked our return line video. Hahahaha!

[fullthrottle]

I felt that the weight of the gas in the tank made it that much harder for the pump to push the fuel back into the tank. regardless I did burn up an inline walboro using that same tank as you because the foam inside of it was coming apart. I only used a filter after the pump and I think bits of foam got into my pump. Check your filters and see if they are clogged. I was having to clean my filter every couple of hours while at the track until I just pulled all the foam out. It took forever for the bits still left in there finally get cleared out of the tank. I really think the only foam that doesnt break down in gas is the very high end tanks. And thanks for clearing up the bottom return line question. I actually switched the return line and pulled the foam at the same time so I suppose I cant say for certain my return line was the problem after all.

[[email protected]]

Don't get me wrong, the weight of the fuel in the cell going agains the fuel coming out of a dip tube or bottom return adds a bit of head pressure, but not enough to matter. *Maybe* .5 or 1psi.

[beems240sx]

That may be my issue. I noticed the foam was at the top of the tank so I pushed it back down. I'll just try yanking it out and see if it helps. As well as clean out that filter. I'm running two filters. I can't remember part numbers but the filter with check valve is by the fuel rail with the finer filter. Without foam what issues will that now cause?

[[email protected]]

If you have the check valve filter downstream of the pump, you have them in the correct order.

The foam is mainly there to keep the fuel from sloshing around, but as mentioned above- not all foam is created equal. There are many different foams on the market that will break down over time, thus causing all kinds of fuel problems. If you take the foam out, I would also be sure to take some time cleaning the cell out to be sure you get all of the little pieces out (if there are any). Even if the foam hasn't broken apart, it could be packed in front of the feed to the pump or something of the sort.

[beems240sx]

I'm going to probably check it out today and I'll report back the findings

[GSXRJJordan]

Small world! Josh @ Fuelab is one of the most knowledgeable guys around, and helped us with our fuel system for the FD. Good to see you here on Zilvia Josh!

Beems, if you have a new pump that's having problems, definitely check that foam and pre-filter. We've blown up more than a couple external pumps due to shoddy pre-filters and foams that had broken down.