Fass Fuel Filters, Learned something!

[jshmohr]

Hey guys this summer I was very proud of myself and found a 2 micron fass 150 fuel filter from my NAPA store! Little did I know it was the wrong filter I put the 2 micron for the water separator! Well in the last few days here in Minnesota it has been dropping into the low 20's and when I have been starting my truck in the morning it would run for a minute and blow the 30 amp fuse that runs the pump:shrug: So what I finally found out after calling Fass a couple of times is that my filter was drawing fuel to hard through that fine of filter, so I spun on a 14 micron Napa #3405 and hopefully all my problems are gone!

[AH64ID]

Did you not have a f/w sep on it at all? Yeah a pump would not like sucking thru a fine media (not sure Wix makes a true "2um") filter with cold fuel!I know you work for NAPA and thus like Wix filters.. but their published data is never quite as good, nor is it really accurate reporting. Nominal doesn't mean anything and that filter is 14um nominal.. which could be anything less than 98.7%, usually around 50%.

[Mopar1973Man]

MN you got to be careful the biofuel (B2) tends to thicken up more so...

[jshmohr]

Yeh I seemed to help but my pump still has been blowing the 30 amp fuse when the truck is cold any ideas? The pump will run for about 15 seconds then blow the fuse I can put a new fuse in and have no problem?

[AH64ID]

If you think it's filter related the BF1212 is a 20 um filter and may help if the fuel is thick, but I am not sure that's your issue. When you first start the truck can you see the feed line collapsing under pressure?How cold has it been?Have you tried slow-blow fuses? Or a 40 amp fuse to see if your really overpowering the system or just tapping the 30 amp range? If your voltage is lower (grid heater) and the motor draws the same amount of juice the amp requirement goes up.

[jshmohr]

I put a 14 micron filter on it now, I don't know if the fuel line is colapsing, and its been in the low 20's to teens but the truck has been in the garage where my engine coolant temp has been around 60 degrees:shrug:

[AH64ID]

I just checked the cross on that filter and it's the cross to a BF1212 so it's should be about 20um absolute.. so about as loose as you can get. They are only rated for about 90 GPH, but then again that's all you can really get in a 1-14"..

[jumpjg]

Yeh I seemed to help but my pump still has been blowing the 30 amp fuse when the truck is cold any ideas? The pump will run for about 15 seconds then blow the fuse I can put a new fuse in and have no problem?

I do not believe a motor would overload if the supply of fuel to it were restricted; actually I think the load would be less since the pump isn't doing any work (put your hand over the end of the hose on your vacuum cleaner & the rpm goes up). I've been reading a lot about aftermarket fuel pumps lately in old post on various forums. A number of posts talk about blowing fuses on their FASS systems. Some say that their fuse-blowing problem was caused by a bad shaft seal allowing fuel to get into the motor case. FASS now advertizes that they have super whis-bang shaft seals. This may have been a problem that was isolated to an earlier production run. I don't have any proof either way that this might be causing your problem, but maybe it will help you. Good Luck! Joe in St Louis

[jshmohr]

Cool thanks but iput a 30 amp circut breaker in and have no problem bu I dont think it solved the problem

[MnTom]

Even B-20 won't thicken enough to cause any issues at the temps we have been seeing. Also the explanation that was given by FASS is a bogus explanation. On ANY pump when you restrict the suction side the amp draw goes down like jumpjg says. If you restrict the pressure side then amp draw increases. When the fuse blows, is the element literally disintegrated and it looks like a flash has gone off in the fuse, or is the element for the most part still there? If it looks lke a flash happened then it means there is a large amp draw and is it is mostly intact it means there is a large enough load to heat the fuse causing it to blow.

[jlwelding]

I can only share my experince with my AD 100, last year it blew it's first fuse and I thought no big deal. A week goes by and it blew again put another fuse, a day goes by again so I go bigger. Five boxes later it finially died, put a 45 amp and it lasted 3 seconds.AD replaced it for free,I still dont know for sure what it was. I am guessing motor drag? Ordered a 150 and when the replacement 100 got here sold it and bearly had any cost in the 150.