FASS Fuel Filtration Systems

[tmw188]

So I’m in the research stage on doing a install of a FASS Filtration System at some point in the future especially with all the fuel I’m burning these days😩. I talked with FASS and a preferred dealer near me and FASS is recommending their new IND100G an alternative filter system newly designed for our applications among others, like large generators.  They said I could use TSD08100 also or the 165GPH model. The IND100G comes with a T to tap into the return line at the engine. This model has the same pump motor in its GPH rating as the TSD is my understanding along with some other changes in the mount I believe. It’s been called to my attention if I’m stating it correctly that installing the T onto the return line near the motor could cause some issues and throw a Check Engine Light and some codes if things are out of spec for the CAPS? You can find some promotional videos for the new IND100G online and on FASS website. I won’t have any answers to any follow up questions you might have for me, I’m looking for questions you might suggest me getting answers to and any input you might have that can help. 

https://youtu.be/3Owx2Fa8Kgw

 

Edited June 6, 2022 by tmw188
Added content

[cbr046]

I tapped the FASS fuel return into the engine return line but at the tank, not near the engine.  Installation was in January 2022, 5,000 miles ago.  No problems. 

Our coach is a 330hp Cummins ISC.  The system installed is the FASS TSD08 100G.  The system fuel pressure runs at 16psi and drops to ~12 psi under full boost, measured at the secondary filter.  That's wayyyy better than sucking fuel! 

It looks like the new IND100G doesn't need a return line, but that also means you're not polishing (cleaning) fuel as you go. 

- bob

[tmw188]

I believe yes it is polishing that’s one of their big selling points. Also if it’s returning  and the pump is running all the time wouldn’t that be considered polishing? Neither the Fass Co nor the dealer mentioned it would not be considered polishing.

Edited June 6, 2022 by tmw188

[jacwjames]

2 hours ago, tmw188 said:

I believe yes it is polishing that’s one of their big selling points. Also if it’s returning  and the pump is running all the time wouldn’t that be considered polishing? Neither the Fass Co nor the dealer mentioned it would not be considered polishing.

I agree, the pump would be polishing since the engine is using a small percentage of total fuel pumped.

My question or concern is you are connecting into the existing return line will it result in a higher back pressure to the CAPS pump.  The FASS pump already is pushing more fuel to the CAPS then it can use, then you add more being returned via the return hose and my guess is it will result in higher pressure in the CAPS system.  I know that the ECM does monitor fuel pressure and will throw a CEL or fault code if the fuel pressure is out of spec. 

I had a fault code come up on my first trip after installing the FASS system.  My symptoms were rough idle, I was filling up the coach and let the engine run.  That's when I found the fault code as shown below.

ENG PID    94 10 Fuel Delivery Pressure         Abnormal Change   7/24/21  7:58
ENG PID    94  0 Fuel Delivery Pressure         High Reading           7/24/21  7:58

Since then I've made it a point not to let the engine idle for any period of time.

But I would assume that the FASS company has worked through this otherwise they wouldn't change the design.

 

[timaz996]

I installed the TSD08 model. I had this on my list of to do‘s and put it off too long and ended up losing my caps pump over Thanksgiving weekend. I finally installed it in March and I am very happy with how it has worked. As for any gain in mileage I am not sure because of the fuel prices this year I’ve slowed down from 65 to 60 and that has gained me a little over 1 mile per gallon. So I’m not sure if the FASS system has anything to do with that. Whether you have someone do it or you do it yourself my point is don’t put it off. There is many threads on Irv2 Monaco Fourm Covering peoples installations so I suggest you read those.

[tmw188]

9 hours ago, Tim-AZ said:

I installed the TSD08 model. I had this on my list of to do‘s and put it off too long and ended up losing my caps pump over Thanksgiving weekend. I finally installed it in March and I am very happy with how it has worked. As for any gain in mileage I am not sure because of the fuel prices this year I’ve slowed down from 65 to 60 and that has gained me a little over 1 mile per gallon. So I’m not sure if the FASS system has anything to do with that. Whether you have someone do it or you do it yourself my point is don’t put it off. There is many threads on Irv2 Monaco Fourm Covering peoples installations so I suggest you read those.

Thanks Tim I’m with you on that. That is the reason I want to do it. I’m not sure which install method I want to do yet.

[cbr046]

The "new" IND100G has 3 ports and still connects to the fuel return line but it doesn't return fuel.  The 3rd port is an air purge port.  It doesn't return fuel to the tank.

- bob

 

[tmw188]

OK I got off the phone with FASS moments ago and this is what he said. The new industrial IND100G model was created for those of us in the RV world and other applications and is more of a universal design and wanted a little bit easier install on their motor. It does push fuel back to the tank through the stock return line but not at the same rate, so the polishing affect is nowhere near what it would be with what most of us have put on thru the years. The filter head is a totally different design and he also answered the question about the back pressure to the CAPS pump and he said that is not a problem it will not create too much back pressure to the that pump it’s built into the design and is too much to explain, but it also does not return the fuel as quickly as the other systems. He said if it was him and if you got the ability he would certainly put it at the tank and push the fuel to the motor and he also recommended for a very little money to go ahead and go with the TSD165GPH even though the 100gph model is sufficient the fact that a lot of us let these RVs sit more than they’re being used the 165 is going to filter and are polish that fuel at a much faster rate. 

 

[jacwjames]

Well there you go, a different design.

Personally I would rather have the increase fuel polishing.  I installed the 100gph system, If I'm driving 65 mph and getting 8 mpg then I'm pushing 92 gallon back to tank.  So starting with a full tank I'm polishing 72% of a tank full.  After 4 hours of driving I'm polishing 96% of the equivalent of what is in the tank.  It will only get higher as the tank goes down so after a day of driving I've polished the tank ~7 times.  Good enough for me.  

[tmw188]

There was a need for a easier install so that’s how this evolved by design. It doesn’t mean it a bad design I guess just different and there are always trade offs. 

[timaz996]

The trade-off I made was to mount mine in the rear were the secondary filter was. Because of the very cramped space I had up by the tank. I honestly don’t think I have lost anything because I’m putting 19 psi to the injection pump at idle. I realize it is easier on the pump to push the fuel then pull it but as I have stated mine is working fine and I am happy with the install.

[tmw188]

On 6/7/2022 at 11:08 AM, jacwjames said:

Well there you go, a different design.

Personally I would rather have the increase fuel polishing.  I installed the 100gph system, If I'm driving 65 mph and getting 8 mpg then I'm pushing 92 gallon back to tank.  So starting with a full tank I'm polishing 72% of a tank full.  After 4 hours of driving I'm polishing 96% of the equivalent of what is in the tank.  It will only get higher as the tank goes down so after a day of driving I've polished the tank ~7 times.  Good enough for me.  

Yeah I agree with the 100gph logic. The extra $50 in cost to get the 165gph pump can go towards additional items needed for the install. 
I guess you could turn the key on while visiting the coach during storage and cycle that fuel thru the filters to keep it moving once a mo let’s say? 

Edited June 8, 2022 by tmw188
spelling

[vanwill52]

No matter which FASS system you install, you will be adding a "bit" of insurance for your CAPS system.  The CAPS system is designed to "tolerate" NEGATIVE 5 PSI.  That means its internal gear pump, which is its "primary" pump, can still supply adequate fuel to the CAPS pump even if there is a significant suction on the inlet side of the CAPS pump.  I do not endorse any of the claims that have been made about the CAPS pump using bypassed fuel for cooling and lubrication, but it does make sense to me.  What does NOT make sense to me on any diesel engine, is to be running the injector pump on the verge of fuel starvation.  No matter what causes that fuel starvation, it does not seem to me fuel starvation is EVER a good mechanical situation for the longevity of the main injection pump.  Yes, of course, it happens regularly when someone's fuel filter(s) become clogged, they lose power, and have to pull off the road and change filters.  In those cases, the main injection pump has become starved for fuel.

Does fuel starvation from a clogged filter do any damage to the CAPS pump?  There are a multitude of opinions out there, but scant scientific evidence.  I'm not sure, but I tend to choose to err on the side of safety.  If I'd had a fuel pressure gage (WITHOUT FASS pump system) at the inlet of my CAPS pump, as I do NOW (since installing the FASS system), there is no telling what I might have learned.  I'm sure I would have seen that inlet pressure at the CAPS pump was much lower than the allowable NEGATIVE 5 PSI allowed by Cummins specs as my fuel filters clogged.

With the FASS system installed, and a remote-reading fuel pressure gage, I can see that at no load my fuel pressure (measured at INLET to the CAPS pump) is about +16PSI.  At WOT, that pressure drops to +14 PSI (with new filters in all three locations).  The difference between fuel pressure at no load, and at WOT is a good indicator of the restriction in the fuel filters due to contamination.  Should that WOT pressure fall to +5 PSI or so, I would assume it's time for new filters.  My FINAL filter (as it enters the CAPS pump) is now a 2-micron filter.

As an anecdotal note, AFTER I installed the FASS system, I had two cases of primary filters becoming clogged within a few thousand miles (WOT CAPS inlet pressure less than 10 PSI, but NO change in engine performance), and in both cases, the FASS primary filter showed significant tar-like residue.  It's now been over a year since I changed a fuel filter, and inlet pressure at the CAPS inlet is still not less than +13PSI at WOT.

In summary, I ABSOLUTELY do not suggest the FASS system will add one iota of HP to your engine.  IT WILL NOT!!  But my experience dictates that it does a GREAT job of "polishing" your fuel and allowing you to greatly increase the length of time between fuel filter changes.  PLUS having an indicator (if you have remote fuel pressure sensing) of when such a change may be imminent.

YMMV

[tmw188]

So let me ask the question with this FASS system setup properly, could you just turn the key on and run the pump once a mo for :30 min or so let’s say while in storage to help “polish” the fuel? Would this harm other engine ignition systems having the key on without the motor running?

Edited June 8, 2022 by tmw188

[cbr046]

If I knew I would be doing that I'd run a separate switch to run with key on (running engine) or run from +12V.

I don't know if leaving the key on without an engine running would trash the ECM or some other component . . . . probably not.

- bob

[jacwjames]

Todd,

In the past prior to my FASS install I've left the ignition key on for over a day not realizing it was on.  I didn't do this intentionally.  But I've never experienced any problems from doing this.

Now with the FASS installed up front passenger side I can hear hear when I turn the key on so I won't be letting the key on by accident.

The way I wired wired mine in I piggy backed off of a IGN ON fuse in my front run bay for the relay that starts the pump.  So if I wanted to run the pump for  while all I would have to do is move the fuse to a different fuse which is always on. 

But when I park my rig for longer periods of time I'll use Biobor (and sometimes Startron) and fill the tank all the way full to minimize condensation.  I usually do this at the pump so on the drive home it mixes.  Doubt I'll have any problem and when I leave on a trip it starts polishing as soon as I start the engine.  Don't think it's necessary to do this any more then that.

[tmw188]

Thanks you guys good ideas given.