FASS question

[steved]

There have been a fwe issues with the 150GPH pump sucking the module dry. This results in motor pitch changes and possibly even cavitation in the system.



FASS's fix is a seperate 1/2" standpipe and bulkhead fitting to draw unrestricted fuel supply.



So, what I am saying is that your gauge may be right. The pump may be working correctly. You may have a restriction in the tank.



FWIW.



Dave

While I agree with this, if there was a restriction in the pickup unit, his guage should have spiked when the return like was kinked... the FASS should have built pressure, even with a restricted flow.



steved

 

[Jed]

The 5gal bucket test that I am going to do this weekend will eliminate the pickup screen or the standpipe as a problem. Still need a small gauge for the test fitting on theFASS.

 

[Fishin Guide]

The 5gal bucket test that I am going to do this weekend will eliminate the pickup screen or the standpipe as a problem. Still need a small gauge for the test fitting on theFASS.

That sounds logical.



Dave

 

[Jed]

Ok now I feel like a dumbass. After everyone saying it is my gauge I got a test gauge and guess what 19lbs. My apologies to my FASS pump and thank you to all who helped me to see the light. I did not want to believe that my new gauge could have gone t. u. in such short order and I certainly did not want to believe that my new gage was never correct. However that is the reality of the situation

My thanks also to Diesel Dan at FASS for taking the time to work me thru a problem that was not related to his equipment I understand his frustration at having all problems blamed on his product before diagnosis.

I guess is part of the paranoia of being a 24valve owner and having to be on my third vp44.

In closing I will be mounting a good, liquid filled fuel pressure gauge on the firewall where the isolator was mounted with a direct tap from the fuel line.

My final question would be is 19lbs too much? I am pretty sure that the test gauge was accurate at 19lbs so I have probably had that since new 35,000 miles or so and it does not seem to be hurting anything.

 

[PRout]

You might want to order the 15-16 lb spring instead. 19 psi is a little hard on the pump. Apparently, 13-15 is optimum. Just be sure to have big enough fuel lines to where your pressure doesnt fluctuate much when under load.

Edited: The "pump" meaning the VP44.

 

[WCounts]

Glad to have been able to help some body.

Diesel Dan chime in and let us know what pressure is safe to run on Jed's fass.

I would think 19psi would be ok if the motor doesn't run hot. I have run my AirDog 95gph at 40psi and it runs warm but not hot. I have heard the AirDog and FASS have the same motor. I have it set at 25psi now because it runs quietest at this pressure.

 

[steved]

Glad to have been able to help some body.

Diesel Dan chime in and let us know what pressure is safe to run on Jed's fass.

I would think 19psi would be ok if the motor doesn't run hot. I have run my AirDog 95gph at 40psi and it runs warm but not hot. I have heard the AirDog and FASS have the same motor. I have it set at 25psi now because it runs quietest at this pressure.

With his being a VP44, I think it would be hardest on the VP44, not the FASS...



I agree with the recommendation of dropping the pressure some... Diesel_Dan can hook you up on that most likely... thoughts, opinions, and readings vary, but it looks like anything between 8 and 16psi is where the VP44 is happiest.



As a side thought... whatever pump you have, set it at the minimum/optimun psi you need as with anything, running the FASS at more pressure than really needed is putting un-needed stress and strain on the pump motor and, even though I don't know for sure if it would, might lead to a shortened pump motor life...



steved

 

[PRout]

Right, I was referring to 19psi being a little hard on the VP44. The FASS is pretty beefy, but the VP is a weak P. O. S.

 

[chazj]

Is the Fass pump adjustable with respects to it's output PSI???

 

[steved]

I believe the FASS II (the stand alone pump) has a spring and ball much like the FASS does... and if so, yes, there are several options as far as PSI is concerned...



steved

 

[LowFly]

Sorry all... . was out of town for a Show in my home state of Texas..... just got back.



Glad to see you figured out your problem. And dont worry about me... . this is my job to give ideas to get to the bottom line.



AS for the pressure... . its very vague... ... we have had people out there that run 22 all day long for over a year with no issue. The VP is set up for about 14-15 PSI as per the check valve on the return... ... . so... . if in doubt... i would run around the 14-15 PSI range. We have a 0. 100" machined fitting that will lower the pressure to about that..... if you are around the 20 psi range.



The HPFP..... i would be very careful on how you adjust the pressure... ... you can exceed the rated PSI of the EM-1001 motor... ... (150 GPH 23-24PSI) (95 GPH 45 PSI)