CP4 FCA Screen from Exergy

[LBZ]

Ultimately, all the fuel must pass through the FCA. The FCA pulls its fuel from the body of the pump where the rotating assembly, cam and roller reside. When the pump desides its had enough and commits suicide, all of the metal debris must pass though the FCA before making its way to the piston and then to the injectors. As it sits the screen on the FCA is the last resort to stop anything from making its way to the injectors. At 60 microns its more of a sand trap. 25 microns is better but no ware near enough to protect the injectors from harm.........

.........2micron makes a bypass kit for the VWs that would likely fit these trucks. It allows fuel to be fed directly into the FCA without going through the body of the pump. Now your main filter is the one that determines what micron size particles make it to the injectors

I think that the hope is the 20 micron might get plugged enough to throw low rail pressure codes causing you to shut down and investigate instead of blowing the bigger pieces into the pumps pistons and injectors scattering the piston section and scrubbing the injectors.

Been thinking of putting one of these FCA deals in my truck as I have no desire to change to a cp3 but I’m intrigued by this vw bypass kit. Wondering if anyone has looked into it further or tried to make it work?

Also has anyone that’s installed one of these had a pump failure that saved injectors?

 

[LBZ]

I just did a little searching and it seems that the 2microntech guy isn’t making those kits anymore.
I’d like to see one just to see how they were set up and see what we need to fit them on our cp4’s.

 

[2004LB7]

There is a lengthy discussion on the TDIClub site about these. Have you seen it?

As far as I know both the CP4 for the VW and the LML have the same design for the FCA

I think someone with a lathe could probably make one quite easily. In this photo the only part you really need is piece on the end, right side, of the tubing

http://s1059.photobucket.com/user/2...Protection Kits For Common Rail?sort=3&page=1

 

[coker6365]

There is a lengthy discussion on the TDIClub site about these. Have you seen it?

As far as I know both the CP4 for the VW and the LML have the same design for the FCA

I think someone with a lathe could probably make one quite easily. In this photo the only part you really need is piece on the end, right side, of the tubing

http://s1059.photobucket.com/user/2...Protection Kits For Common Rail?sort=3&page=1

The problem with the design pictured is it will require a lift pump capable of +55psi to function properly. Only certain model lift pumps can meet those requirements reliably. I have already tested a design that works in that manner and I am working on a 2nd design that may allow us to run without a lift pump. Depends on flow rates after testing.

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[LBZ]

The problem with the design pictured is it will require a lift pump capable of +55psi to function properly. Only certain model lift pumps can meet those requirements reliably. I have already tested a design that works in that manner and I am working on a 2nd design that may allow us to run without a lift pump. Depends on flow rates after testing.

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Why such high a pressure?

 

[LBZ]

There is a lengthy discussion on the TDIClub site about these. Have you seen it?

As far as I know both the CP4 for the VW and the LML have the same design for the FCA

I think someone with a lathe could probably make one quite easily. In this photo the only part you really need is piece on the end, right side, of the tubing

http://s1059.photobucket.com/user/2...Protection Kits For Common Rail?sort=3&page=1

I did a bit of reading. I’m still trying to understand 100% on how it flows.

 

[coker6365]

Why such high a pressure?

The mechanical pump on the CP4 feeds the FCA, similar to a CP3. That mechanical, or positive displacement pump, actually does a very good job and is capable of very high pressures. When dealing with an FCA that is basically a solenoid valve to control how much fuel enters the plungers, a certain amount of head pressure is needed otherwise it will not allow enough fuel to the plungers. To top it off, the LML I injectors need about 60psi on the return side to function properly. It will idle with 15psi at the FCA if you bleed an injector line to start it, but it will immediately fall on its face off idle under a load since the plungers are starved.

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[2004LB7]

Thats a good point. The VW tdi has an axillary pump that boost the fuel pressure to approximately 75 psi. So this part would have no issues working on it.

Since the LML has a gear driven pump mounted on the back and internal ports to feed the FCA. Bypassing the normal ports would end up supplying the FCA with what ever your lift pump is set at. This will also reduce the flow through the body of the pump wich is also the cam, roller and follower's lubrication. The only fuel flow will be through the bleed port/pressure relief

With the reduced flow of lubricating diesel, I think this would cause it to run a lot hotter and reduce its effectiveness. This may be why some experienced CP4 failure shortly after installing the bypass

I wonder if the bypass could be altered for full flow and the plump it to a second filter and then have that feed the bypass to the FCA. That way you still retain the use of the gear pump and good flow through the body with the additional filter on the FCA

 

[LBZ]

Thats a good point. The VW tdi has an axillary pump that boost the fuel pressure to approximately 75 psi. So this part would have no issues working on it.

Since the LML has a gear driven pump mounted on the back and internal ports to feed the FCA. Bypassing the normal ports would end up supplying the FCA with what ever your lift pump is set at. This will also reduce the flow through the body of the pump wich is also the cam, roller and follower's lubrication. The only fuel flow will be through the bleed port/pressure relief

With the reduced flow of lubricating diesel, I think this would cause it to run a lot hotter and reduce its effectiveness. This may be why some experienced CP4 failure shortly after installing the bypass

I wonder if the bypass could be altered for full flow and the plump it to a second filter and then have that feed the bypass to the FCA. That way you still retain the use of the gear pump and good flow through the body with the additional filter on the FCA

This would make sense to me and how I would want to route the flow. I wonder if it could be done or would need to be done with a remote mounted FCA?

 

[Chevy1925]

Why not just run a dodge lift pump? they are 60psi IIRC

 

[LBZ]

Why not just run a dodge lift pump? they are 60psi IIRC

Fuelab makes pumps good for up to 125psi also.

 

[Chevy1925]

Fuelab makes pumps good for up to 125psi also.

i guess i said that wrong, i meant a lift pump meant for a dodge like a FASS or AD. they are somewhere around 60psi. The new drop in tank style one for dodges is pretty sweet too. be cool if those would work on ours.

 

[coker6365]

Thats a good point. The VW tdi has an axillary pump that boost the fuel pressure to approximately 75 psi. So this part would have no issues working on it.

Since the LML has a gear driven pump mounted on the back and internal ports to feed the FCA. Bypassing the normal ports would end up supplying the FCA with what ever your lift pump is set at. This will also reduce the flow through the body of the pump wich is also the cam, roller and follower's lubrication. The only fuel flow will be through the bleed port/pressure relief

With the reduced flow of lubricating diesel, I think this would cause it to run a lot hotter and reduce its effectiveness. This may be why some experienced CP4 failure shortly after installing the bypass

I wonder if the bypass could be altered for full flow and the plump it to a second filter and then have that feed the bypass to the FCA. That way you still retain the use of the gear pump and good flow through the body with the additional filter on the FCA

This is essentially what we are testing for the 2nd design. The real question is, can you flow enough fuel out of the FCA feed side of the housing, through a free flowing 10 micron or less filter, and back to the FCA inlet without sacrificing flow from the mechanical pump to hurt performance.

 

[coker6365]

i guess i said that wrong, i meant a lift pump meant for a dodge like a FASS or AD. they are somewhere around 60psi. The new drop in tank style one for dodges is pretty sweet too. be cool if those would work on ours.

The AirDog pump peaks around 45-50pis if I recall correctly. The Fass pumps using the EM-1001 motors, which is every Duramax pump less than 220gph, will only reach 45-50psi as well. The EM-1002 motor is needed to reach the higher pressures, which is found on the 220gph pumps or the Ford pumps that replace the stock lift pump. I have an extra 160gph Fass sitting on the shelf, we can max it out and see what it will produce but I doubt it will be enough to operate the FCA properly. 50psi or less definitely reduces the performance, 60-70psi seemed to be the optimum range but I have also ran it at 85psi with no issues as well.

 

[02greysixer]

Ford 6.7 supply pump would work perfect. The Ford cp4 doesn't use a gear pump. Only the electric pump. My truck maintains 60 psi supply pressure up to 100mph on the 600 rwhp horse tune.

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[coker6365]

Ford 6.7 supply pump would work perfect. The Ford cp4 doesn't use a gear pump. Only the electric pump. My truck maintains 60 psi supply pressure up to 100mph on the 600 rwhp horse tune.

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Yes it would, however, by the time you figure the cost it is not feasible for those who already have a lift pump. It would be a cheaper alternative for those who do not already have one though.

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[2004LB7]

I dont think any lift pump is going to solve the problem with the use of the FCA bypass. The problem is now you have split the flow of diesel between the body and FCA whereas before all the fuel went through the body.

These pumps are delicate enough that I don't think it is a good idea to reduce the fuel flow through the body of the pump

I think some of the ideas we are proposing are enough work and cost that we are better off putting a CP3 in it

But if you where really determined, you could drill and tap the side of the pump and run a line to a filter then to the FCA bypass. That way you maintain the same fuel flow through the pump and wouldn't need any high pressure lift pump

 

[LBZ]

That would be the ideal flow pattern. Have a piece made that is dual ported somehow and goes where the FCA normal fits, so the flow comes into this piece, out and then through a filter, then through the FCA which is remote mounted one way or another, and then back to the special piece and into the piston side of the pump.

If the way I’m understanding how it normally flows through the FCA it goes in through the screen and out through the bottom right? So the piece you would need would have to have similar porting with a stem in the middle so to speak that return flow after the filter goes through the middle and is sealed from the flow coming in around it. If this makes any sense.

Would be tricky to make and probably require a cnc to build. Or a custom modified oversized banjo style of connection where the flow from the pump body goes around the bolt not through it and out the fitting in the side and the filtered fuel goes in the top of the bolt down through the inside and into the piston chamber.

 

[2004LB7]

LBZ, you really only need to change how you feed the FCA as the feed to piston is as you guessed, into the screen of the FCA then out the hole on the bottom then the port at the bottom flows to the pump piston. So if the feed to the FCA was filtered then all of the fuel to the injectors would also be.

If you look closely at the bypass, it is essentially just an extension to the FCA and it locates the feed to outside the pump body and at the same time blocking the original location

The flow out the bottom of the FCA still goes to the same place at the bottom of the FCA bore.

Remote mounting an FCA would require two parts to do. One to hold the FCA and another to put it back into the pump piston. Plus whatever additional plumbing needed. The way the current bypass is done it is really just an extension where the inside that the FCA mounts in is the same as the pumps and the bottom of the bypass looks like an FCA in shape and dimensions.

I have a CAD drawing of one I was working on on my home computer. I'll see if I can post up a few renderings of it and maybe dimensions.

 

[LBZ]

I understand the current design but doesn’t the current design split the flow? As in not all the flow goes through the body. I’m talking about keeping the flow design stock while just extending the loop through a filter before going into the FCA. Hence no need for a hp lift pump.