FASS pump for liberty

cumminspilot · **Posted:** Sun Jul 15, 2007 7:35 pm

New to liberty, not to diesel. The filter assembly scares me after spending too many hours on this site reading about it.
First question; which plug is for the fuel heater, in southern cal I do not need and it seems to be seeping; what is the other plug for? I know that the bottom is for wif sensor. Do I get cel if I unplug heater?
As a temporary fix I would like to unplug heater and what I think is fuel temp sensor.
The cat filter seems like a good way to go but without a lift pump it also scares me.

My 02 cummins was one of the problem ones that lost an injector pump about 80,000 the short version of the story is that is the event that started me down the road of modification. I have learned enough to be dangerous and have the appropriate pile of broken parts to prove it.

That being said and with the understanding that I have read most of the appropriate threads concerning the filter housing and problems associated with it WHY NOT a fass pump? You get a seperater and filter and positive psi at the injector pump and you can unbolt the stock assembly and plumb directly to pump with no banjo bolt.
Many will argue that it is expensive and without room under truck and overkill. However after reading drharv's and others problems with air this would seem to eliminate the source. The fass is actually a fuel air seperator I have had one for 80,000 and never had a problem with it (others have had problems).

I know that some on this site have/are running lift pumps with good results. Does anyone have a guess what pressure they have at the pump? I very much want to try this and am willing to spend the money and hopefully I can talk fass into trying.

I am sure that this will not be for everyone but I have not had a fuel heater on my truck for 3 years and startup with #2 and stanadyne or schaeffer additive @25f was not a problem.
Basically I want to eliminate the filter housing completely the cleanest way possible without setting off the cel ; any thoughts, comments, questions or smartass comments would be most welcome.
Sorry for such a long first post.

Cowcatcher · **Posted:** Sun Jul 15, 2007 8:33 pm

WELCOME!!!

Facing the filter the connector on the right is the heater and the one on the left is the temp sense. The majority of the problems are likely related to the plastic puck between the filter and the head that house the connections for the temp sensor and the heater.

I am not the expert here on this issue but part of the problem with filters, heaters and heat sensors are related to the common rail design, the high pressure pump and the ECU controling them. If I understand correctly I don't believe disconnecting the heater will thow a code but the ECU likely senses the temp of the fuel and ajust the pump accordingly. Some here have disconnected both but it seems most often that the leak occurs between the head and the puck or at the heater connection. I don't think there would be a reason to disconnect temp sense and that might affect operation. I am not sure that anyone has specifically determined that the heater being connected would eliminate the leak there.

I don't think anyone has specifically tried a FASS but there has been suggestion of air seperation filters. Check the post on "filters, filter heads and lift pumps" as there are links in it to most previous recent topics about these issues.

In my opinion the fuel head is enough of a problem that Jeep will be required to replace it with a RACOR like the European 2.5 CRD or replace the plastic puck with a more durable design. The FEDS are looking at it now as a safety issue.

The lift pumps being used are very low pressure. Again if you check the past posts I am sure someone has posted it but there was concern that putting hardly any pressure on the system with a lift pump would be a problem. I believe the number I recall being discussed was to keep it under 3 psi.

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

I can see where you are coming from and getting rid of the stock filter assembly would be great. But I think there two important question to ask yourself. 1) Where you gonna put a FASS. That thing is big. I can't think of a place to put it on the little KJ. Then there's the plumbing of the return line, etc. 2). Why? The CRD doesn't really have a fuel delivery problem and a mechanical pump in the CP3 is simple. (Remember the old KISS addage). The real problem is the filter head and filter. The Racor seems to be a good solution, if it will work. I can understand your concern about sucking fuel thru a 2 micron filter from the tank to the CP3. But, so far, those that have done the CAT filter don't seem to have a problem.

cumminspilot · **Posted:** Tue Jul 24, 2007 1:41 am

thanks for the replies Cowcatcher and Tinman and by the way thanks for the heads up on this site over on the tdr. Sorry I have not been back on but have been working a lot and driving a lot to get there.

For Cowcatcher thank you for the locations of heater and temp sensor on filter and another question is can you explain anything about how and what the fuel temperature sensor does? Does it function just to tell the heater when to turn on? I have read posts that allude to some performance gains without it pluged in. In short what do it do?

Tinman
Because you are the owner of a modified 24 valve you know what I am getting at as we live by the fp guage.
I agree location would be tough the filters could be shortened with the right part numbers or the single setup could be used with a combo seperator and filter and yes install would be an adventure.
but to be honest the lack of positive pressure just bugs me. I just cant get into the mickey mouse factory setup but I will live with it for a little while.

thanks for all of the input

Cowcatcher · **Posted:** Tue Jul 24, 2007 2:00 am

I don't consider myself an expert just a learner. I understand that the ECU manages the fuel pump and adjusts fuel rate to the injectors based on the fuel temperature. I don't believe the heater has any involvement and is simply a thermostat controlled device. Many have disconnected the heater and a few the temp sensor. In 2004 export 2.8 CRD's and earlier 2.5 CRD's the Racor unit (425?) was used instead of the current one by the way.

There may be a more significant issue at play with hot weather and hot fuel that is creating a problem with air. The engine compartment heat and compression of fuel in the high pressure pump may be excessively heating return fuel to the tank which could be heating the fuel on a 1/4 full or lower tank to between 120/140F under slow driving conditions followed by a short period of parking resulting in air in the system.

cumminspilot · **Posted:** Tue Jul 24, 2007 2:11 pm

Cowcatcher
I would think that the air you are getting me be more of a result of air leaks at filter getting worse when hot parts expand and allow more air in system. Since we have a negative pressure system air is drawn in. With a positive system you just have a small fuel leak.
Given the issue of heat soaking that is why I would like to explore a remote location for the filter away from underhood heat. I understand that I willnot have a fuel temp sensor but I am willing to deal with that.
Please comment

dgeist · **Posted:** Tue Jul 24, 2007 2:33 pm

cumminspilot wrote:

Cowcatcher
I would think that the air you are getting me be more of a result of air leaks at filter getting worse when hot parts expand and allow more air in system. Since we have a negative pressure system air is drawn in. With a positive system you just have a small fuel leak.
Given the issue of heat soaking that is why I would like to explore a remote location for the filter away from underhood heat. I understand that I willnot have a fuel temp sensor but I am willing to deal with that.

Been looking at the same idea but with a simple replacement in the stock location (Racor or similar). I believe the plastic puck is doing most of the harm (and I may be wrong, but hey... what can you do

. It has crappy seals, it has a poor location for a heater, and it thermally insulates the filter body from the head (and body of the vehicle). So, replacing it is a simple job with the obvious loss of that sensor... well, there are lots of sensors that work the same way made for oil and coolant temps in engines. All that's needed is one that fits one of the accessory ports on a filter head and has similar electrical characteristics to stock.

Dan

Cowcatcher · **Posted:** Tue Jul 24, 2007 4:27 pm

cumminspilot wrote:

Cowcatcher
I would think that the air you are getting me be more of a result of air leaks at filter getting worse when hot parts expand and allow more air in system. Since we have a negative pressure system air is drawn in. With a positive system you just have a small fuel leak.
Given the issue of heat soaking that is why I would like to explore a remote location for the filter away from underhood heat. I understand that I willnot have a fuel temp sensor but I am willing to deal with that.
Please comment

Actually I have not experienced air leaks but many others have. Me, just crossing my fingers and watching the puck as I think that is where the majority of the problems are too. Until I know for sure my CAT is resting comfortably in its shipping container.

Right now there are a lot of guys much smarter than me chasing multiple solutions here for everyone with the Kennedy lift pump, the FASS, line insulation, Racor heads and filters and perhaps fuel coolers. With all that brain power working at some point the solution will be arrived at.

Another solution untried is to remove the puck and despense with the heater and temp sense. If the temp sense is not required and you are not in a cold climate it would seem this would be the best solution and doing it with the CAT filter.

cumminspilot · **Posted:** Wed Jul 25, 2007 12:40 am

will it seal without the puck?

Cowcatcher · **Posted:** Wed Jul 25, 2007 2:37 am

We should ask Greg, Lubrication Specialist, that. Greg made the Cat adapter and had the head all apart. While he was doing that not many were pointing the finger at the puck as evil, only that it was a poor design. Not many were considering abandoning the heater and temp sensor. As far as I know that is the only reason for the puck so removing it should work but one might need to mill a new adapter for either the stock filter or the Cat that was shorter to allow for the missing puck.

Personally I live in an area that can easily reach belw -30F so I am not sure I want to remove the puck until we have screamed at Jeep loud enough to require a recall and replacement with something similar but dependable. Since we know the RACOR was used on 2.8 CRD in 2004 before NA introduction then there should be a factory RACOR solution to the whole problem.

Kniggit · **Posted:** Wed Jul 25, 2007 10:23 am

Ever stop to consider that the Factory cure to the problem with Racor filters is the Bosch Filter? :-)r

K

ATXKJ · **Posted:** Wed Jul 25, 2007 5:36 pm

Kniggit wrote:

Ever stop to consider that the Factory cure to the problem with Racor filters is the Bosch Filter? :-)r

K

Yeah - but the factory's definition of a problem was $1 a unit more initial cost.

Cowcatcher · **Posted:** Wed Jul 25, 2007 7:09 pm

Yes and drharv's Bosch filter head sucks air, destroy's his Bosch fuel pump and it is Cat's fault! Of course there was all of his screwed up wiring too and I suppose that was the fault of the Cat as well. :evil:

Joe Romas · **Posted:** Fri Jul 27, 2007 8:15 am

Cowcatcher wrote:

Yes and drharv's Bosch filter head sucks air, destroy's his Bosch fuel pump and it is Cat's fault! Of course there was all of his screwed up wiring too and I suppose that was the fault of the Cat as well. :evil:

All the more reason to tread lightly on mods in the filter head area :cry:

My diesel experience tells me a low pressure booster pump down by the tank is the best solution :oops:

The CAT filter with more filteration is indeed better for the pump but may be just too much for the poor filter assembly we have and allow too much air in :roll:

First we need more filterhead failures reported to the feds to get a better replacement. I still wonder what the service history was on drharv's CRD before he bought it :?:

FASS pump for liberty

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