Mike S

1st. Is the FASS supposed to run continously or intermittantly?
2nd. Does it run quietly or noisy?
3rd. How much hp can the FASS handle?
The reason that I am asking is because my FASS runs continously and a little noisy, I hope that this is normal. The other reason I ask is because with my TST on 5,5 I have hesitation at higher RPM's almost like it is starving for fuel. Thanks, Mike

yzfr6

i think i did read somewhere that you could here the fass at idle, dont have one.
hope that helps

OOPS

Newbe ? What is a FASS and what does it do???

AK RAM

Fuel Air Separation System (I think that is it). It is a fancy lift pump replacement that also does filtering and air removal duties.

It runs continuously.

It can handle more horsepower than the fuel rail can support.

I recently added my FASS as well and have been meaning to post almost the same question. It is a noisy bugger, but I can't hear mine from inside the cab at all. Outside at idle, I don't hear it unless I am specifically listening for it. I think the noise level is acceptable.

My question was going to be concerning the type of noise it is making. When I first primed the pump, you could definitely tell when the fuel hit it. There was obviously a lot of air going through the lines and in the filter that was being pushed out. Very noticeable when all the air initially went through the gears. However, I've put quite a few miles on it and it still has that sound. I can let the truck idle and lay on the ground and listen, and you can hear what sounds like large quantities of air constantly hitting the pump, like big air pockets being sucked into it. Very distinctive sound and definitely more than you would think would be present in the tank. It sounds like a water hose when you first turn it on and the air is being pushed out. I asked DPP about it and they said that it was normal, however, I'm not sure I conveyed what I meant by a lot of air coming into the pump, as I think it is excessive. I don't know anyone up here with a FASS to compare it to. Does this sound like what you are experiencing Mike?

If it is normal, that is fine, but if my installation is somehow introducing air into the system, I'd like to find the culprit before it causes damage. I got to looking around and I noticed that the quick disconnect that slips onto the tank fitting is not very tight at all. Other than a Racor heater, that is just about all there is between the FASS and the tank where large pockets of air could be getting in. I removed it and re-inserted it according to the instructions and it just kind of flops around on there. I am beginning to think the FASS is sucking in air at this connection as it is not tight at all. Actually, the more I think about it, the more I can't see how it is not sucking in air at this fitting. It is really loose (by my standards). Is this quick disconnect fitting rather loose on everyone else's FASS? More importantly, does everyone else's FASS seem to run "smooth" or can you hear what sounds like air pockets being sucked into the pump?

Mike, on the hesitation, I had the same thing. I had the original "hot" program on my TST. I sent it in for a reflash to cure the miss problem at low RPMs and upon return noticed hesitation somewhere between 2100 to 2400 RPMs during acceleration with TST on 4/4 or higher. I originally thought the same thing, out of fuel as I was still on the stock lift pump at the time and didn't give it much thought. However, I talked to TST a few weeks later and they said quite a few folks had complained about that and they had an even newer reflash to take care of it, so I sent it back again. I can't really say that I noticed it after the latest flash as I didn't pay much attention to it, but it didn't jump out and get my attention either. Might need to give TST a call. They can look up the serial number of the unit that you have and tell you if you have the software version that folks complained about.

Any comments about the FASS is greatly appreciated. Love the steady 14+ psi at WOT.

Brian

localnet

AK

Where did you get the Racor heater? Difficulty installing and where?

Mike

AK RAM

I picked it up locally. Install is super simple. It comes with all of the fittings and clamps required and the fuel line supplied with the FASS slips right on. I just had to supply the wire. I mounted it about a foot and a half before the FASS.

You have the Air Dog? Since the male end of the quick disconnect fitting at the fuel tank is not something that can be easily swapped out, I assume the Air Dog uses the same fitting? How loose is the quick disconnect in your setup?

BigBlue

AKRAM, most people I've talked to with the fass have removed the quick connect and just shoved the line on there and tightened it down with a hose clamp. They had the same symptoms as you and that eliminated their problem.

AK RAM

Outstanding. That is what I was thinking. I'll have to give that a shot.

gristle missile

i just got mine done yesterday and it does run loud as hell and it's annoying i can hear it in the cab and it sounds sloshy much like a garden hose being turned on, when it was first on it didn't sound quite like that so i'm not really sure if it's normal or what but i'm gonna wait a minute get some more input and see what's up

Roger rodbolt

I work for Fuel Preporator and our model 135A is the same size as the Fass. It too is noisey, the filters hang below the truck and it will not work nearly as well as it does on Class 8 trucks with 12 and 14 litre engines. That is why we designed the AirDog, a smaller unit specifically for pickups. I have an AirDog my '04 CTD (which formerly had a Fass) and it is very quiet compared to the Fass or our 135A. No problems with surge or pressure fluctuations when below a half of tank and you can fill up the truck while idling. HTH's, Larry Crawford

AK RAM

I got around to removing the quick disconnect fitting today that attaches the hose to the tank. Just removed the fitting and slid the hose over the nipple on the tank and tightened up the clamp. It seemed to help a lot. I still hear some air pockets hit the pump from time to time, but not anywhere near as bad as before. It is a little quieter as well. Understandable with the pump not cavitating so much. Still a noisy electric pump, but can't hear it in the cap at all at idle or cruise. 15.2 steady lbs of pressure.

Haulin_in_Dixie

If it sounds like it is getting air, it is. The only time I hear mine is when I hit the key before starting. But the sound is not annoying. It was when it was getting air. I went to a bottom feed to cure the air and feed problems.

Roger Rodbolt, mine works just fine and smooth, but the air pickup had to be taken care of. Best purchase I ever made. I have run it out of fuel, put some in, bump the starter, start it up. Same with changing a filter, put it on dry, bump it a couple of times, start it up.

If mounted under the pickup bed it would not hang filters below. Where i have mine mounted it is a little lower. Not sure what the pressure should be on the common rail. But I assure you the capacity is way over what is needed.

Roger rodbolt

Haulin...,

I glad that your unit is working well. The old big unit that I won Muncie and Scheid's when sledpulling with my '98.5 truck was purchased from Brad over four years ago when he was with Fuel Preporator. That unit flows about the same as the Fass but is physically larger! I have a bit of experience with the newer units too. Be careful in the Alabama heat...........the Fass is rated at 144 gallons per hour and from what I've seen on the test bench that is conservative..............say (for round #'s) it flows 150 gph and you have 10 gallons of fuel in your tank on a 100 degree day. In 30 minutes of city driving you have just repumped that 100 degree fuel 7.5 times and cycled back to the tank. Shoot your fuel tank with an infrared heat gun and see what it reads. Pumps are just like an air compressor, they heat the fluid.......great in the winter-not so good in the summer. Heat is a major killer of VP-44's......................it kills the electronics (can weaken other parts) as opposed to the weak factory lift pumps killing the mechanical side of the VP-44 due to lack of lubrication. Just a heads up. I'm not belittling your system but hope to save you some grief. If you are going to run the Fass or any other super capacity system it's a good idea to run on the top half of your tank. The Fass noise is a much bigger issue on the 3rd Gen. trucks, we've sold numerous AirDogs to replace it just on the noise issue. Larry

Haulin_in_Dixie

Larry, thanks for the heads up on the heat. Will be checking...

OT-OF-Here

I have the FASS and I only hear it at startup and it's not at all obnoxious. About the heat consideration you brought up,...I guess that's why D-Max (I believe I read this previously) has a cooler back by the tank. Guess a guy could easily adapt their cooler.