Is it bad to rigid mount a fuel pump??

[psychobilly]

Our fuel pump failed in lap 21 of endurance. It was rigid mounted. Could this have contributed to its failure? The other possibilities are particles getting into it, or just plain bad luck in getting a bad pump. Any experiences with fuel pump failure?

We should have put a 50 amp fuse in and let the SOB burn up. At the least it would have lasted the extra...I don't know...70 seconds!

[psychobilly]

Sorry, forgot to mention our school name...University of Maryland.

[Kirk Feldkamp]

Do you have a pre-filter before the pump? How are you defining failure? Loss in pressure or just flat out doesn't work anymore? The other bits in the system, most notably the FPR, can contribute to you thinking that the fuel pump is toast when it's really not.

-Kirk

[Dan G]

Did you use an internal pump externally?

Internal (in-tank) pumps are designed to be cooled by the fuel they're submerged in.

[D J Yates]

Last year, a jammed fuel pump ended our whole 5 minutes of testing before comp. It was later fixed by disconecting and running backwards. There was no filter before the pump, and even though we were careful cleaning the tank, there must have still been some swarf in there.

The engine died mid-way through endurance. I can't remember how we reached the conclusion, but we diagnosed the fuel pump again.

[Mike Cook]

The pump is an external pump and also has a filter between it and the fuel tank. It is possible that the fuel filter is clogged, I'm not sure yet. The fuel pump still works, however it is drawing 2-3 times that amount of current its rated for. We were using a 15 amp fuse on it, which worked through all of our testing and 21 laps of endurance. It then blew. We replaced it with a 20 amp. After getting home, we tried the car again and the first time we went WOT, the 20 amp fuse blew. Thanks.

[Charlie]

Yes fuel pumps are very sensitive to vibration and you should mount them in some kind of non-rigid mounting. Most external fuel pumps come pre-packaged with some sort of AV mounting.

The filter might be your problem too; a filter as in paper style is not recommended before a pump, it can be too restrictive and cause failure. A pump should have only a screen. It's not designed to feed from a negative pressure and it's tough on the unit. A high mounting might have the same result.

A little off topic but I would recommend using a fusible link or slow-burn fuse for motors like fuel pumps and fans that can have high current peak at startup. They won't be as likely to pop for a spike that wouldn't hurt the electrical system, and IMO fusible links are more robust as they are in-line and don't have to rely on a contact-only connection. This wouldn't have helped you in this case but just an FYI.

[BStoney]

What kind of pump are you using, there is something seriously wrong if you are blowing a 20 Amp fuse....let me know and I may be able to help more...

[drivetrainUW-Platt]

did you run it out of fuel?

[Mike Cook]

No we didn't run it out of fuel and the fuel pump in question is a Walbro GSL393.

[John Bucknell]

The housings of external pumps are actually very tight clearance to the turbine. So clamps that deform the pump are a VERY BAD IDEA. Most race applications will locate with a slightly loose 'cup' and/or rubber isolator and use hard line with fittings to keep the pump from moving around.

[Engine Dude]

Hey dudes,

Is it better to use an external or internal fuel pump? I know that for external pumps you need to mount them lower than the tank cause they hate pumping against gravity. Is there some kind of space saving factor with an internal pump?

Also what pumps are people using?

Regards

Sam