[KansasDiesel]

Idea for my ’96 PSD. The link below has 2 different diagrams of an idea to remove the existing fuel system in the truck and installing either 1 or 2 electric pumps. It also uses Fordnut 74’s idea to tie into the common rail system in the heads. Both systems will return to their respective tanks. Will this work? Has anyone remove the fuel system and installed an electric pump type system? Any ideas on how to block off the lift pump hole once the existing pump is removed.

http://pg.photos.yahoo.com/ph/kcveggiediesel/album?.dir=/b7a3&.src=ph

I would like to use the single pump system if there are no issues.

I would appreciate your feedback. Thanks

 

[freds]

[ QUOTE ]
Will this work?

I would like to use the single pump system if there are no issues.

I would appreciate your feedback. Thanks

[/ QUOTE ]

Well it could be made to work, though you are removing some of the redundancies that FN74 has with his setup where the WVO never flows though a single point of failure that is required for running on diesel. (Okay it goes though the injectors, but there are eight of them.)

The primary difference is that you are introducing the fuel pressure regulator and fuel pump volumes into the required purge cycle time and you would also want to sequence the valves to not contaminate the diesel with WVO.

So to purge you would want to delay switching the tank return while diesel is filling the fuel pump, head rails and the regulator, once these items are purged then switch the return to the diesel tank.

That said you would avoid the problem with the engine driven pump peaking and over powering the WVO side that I have experienced in the past, though I think I have solved that with adding a third check valve on the WVO tank feed line.

Your setup would also require a heated filter to boost the temp of the WVO, in FN74’s system the WVO is recirculated though the heads and is quickly warmed to the desired temp by the thermal mass of the heads.

 

[BlueMule]

Im pretty sure the guys with the 94-97's that have upgraded to electric fuel pumps just use a freeze plug in the hole where the lift pump used to be.

 

[KansasDiesel]

[ QUOTE ]

Well it could be made to work, though you are removing some of the redundancies that FN74 has with his setup where the WVO never flows though a single point of failure that is required for running on diesel. (Okay it goes though the injectors, but there are eight of them.)

The primary difference is that you are introducing the fuel pressure regulator and fuel pump volumes into the required purge cycle time and you would also want to sequence the valves to not contaminate the diesel with WVO.

So to purge you would want to delay switching the tank return while diesel is filling the fuel pump, head rails and the regulator, once these items are purged then switch the return to the diesel tank.

That said you would avoid the problem with the engine driven pump peaking and over powering the WVO side that I have experienced in the past, though I think I have solved that with adding a third check valve on the WVO tank feed line.

Your setup would also require a heated filter to boost the temp of the WVO, in FN74’s system the WVO is recirculated though the heads and is quickly warmed to the desired temp by the thermal mass of the heads.

[/ QUOTE ]

Freds,
Thanks didn't really consider the 2 seperate systems except where it goes thru the head, but that would be more of what I would want. How is yours plumbed to facilitate a totally 2 seprate system. Even using the existing filter and pump.

I am already used to the delay switching for purging, that system is on my MB. I would like an automated system but for now budget restraints allow that not to happen

Heated filter was in the plan.

I didn't know FN74 did a return loop system. I am not familiar with the way FN74 plumbed in your system, That is why I am seeking help here. My MB is closed loop but have had some problems with that.

I am very close to ordering all that I need. But want a system that will work and not put me stranded on the side of the road.If FN74 was still around I would be ordering from him. But it seems like you have the only pre '99 that has his type of system.

 

[KansasDiesel]

Thanks BlueMule, i will try that.

Freds, Looking at it again, The only thing that would make my 2 pump system totally independent of each other is adding another FPR, and removing the 3 port purge valve.

How do you stop the veggie from flowing into the diesel FPR? is that return line shut off?

 

[freds]

[ QUOTE ]
I didn't know FN74 did a return loop system. I am not familiar with the way FN74 plumbed in your system, That is why I am seeking help here. My MB is closed loop but have had some problems with that.

I am very close to ordering all that I need. But want a system that will work and not put me stranded on the side of the road.If FN74 was still around I would be ordering from him. But it seems like you have the only pre '99 that has his type of system.

[/ QUOTE ]

Here's what I currently have in my truck and it seems to be much better since I added the backflow prevention check valve.

The only way to screw this up that I have encountered so far is to introduce a lot air into the WVO side of system, which I have done by having a fuel pickup that leaked and running the WVO tank dry because I hadn't gotten around to hooking up the fuel level guage for that tank. The solution is turn off the WVO and crank it a lot, helps to open the purge valve to get the air out of the heads quickly.


WVO side

Tank-->>Back flow prevention check valve-->>loop Mixing T->>Fuel pump -->> Filter->>Check Valve-->>mixing manifold -->> to engine heads -->>from engine heads -->> WVO fuel pressure regulator -->> Line back to mixing T

Purge path

Inlet to WVO Fuel pressure regulator-->>WVO purge valve-->>return line to tank


OEM Side

Tank-->> Fuel Pump-->>Filter-->>Line off to mixing manifold with check valve-->> oem regulator-->> return line to tank

Enjoy