I've got an "odd" fuel system idea...let me know what you think

Zeppelin654

Zeppelin654

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I've got a 92 rclb with a 96 12v ppumped motor. I currently have a hellman sump going into a 5 micron donaldson filter, going to a 2 micron wix filter, going into the stock line to the injection pump. fuel heater is removed and stock lift pump/hoses, etc are brand new. I also have the adjustable tork tech overflow valve maxed out. I see about 25-27 psi at idle and higher about 35-40 during normal driving. I don't know what it is with the pedal to the floor. I have brand new 5x.016's from infinite performance and full cut dv's, as well as, 4k gsk. It is single feed currently

I feel like I should have just maybe done a fass or airdog from the get go, but I like the idea of the mechanical lift pump for reliability and longevity. I know of people adding a pusher pump inline with everything such as a procomp black or holley black. I hear theres a good chance those fail sooner than later and mainly because they arent rated for diesel fuel.

This got me thinking....I wont usually be ripping on it everywhere, but for when I do, it'd be nice to have a pusher pump or some other form of a fuel pump I could flip a switch to turn on and then have 50-60 psi and keep the pump and top end power happy.

SO:

What I'm thinking is....don't touch what I have now, HOWEVER;

- put a y fitting into the line going from the sump to the first fuel filter

- 1/2" line from the y fitting to another filter like I already have mounted on the frame

not a good picture, but the truck isn't at my house at the moment:
heres the first filter:
12122512_10153390882079064_2216999098641393075_n.jpg


- then, from that filter, go to a fass adjustable fuel pressure pump such as this:

61429702651dc2a71c9c29.jpg


http://www.fassride.com/shop/diesel-fuel-pumps/adjustable-diesel-fuel-pumps.php

- and then go half inch line right to the front port on the injection pump

- Simply run a hot wire right to a toggle switch (off/on) and give the pump power from the switch and ground it of course. When you want more fuel pressure....hit the switch to turn it on and BAM go from ~35 psi to ~55 psi fuel pressure

IF you guys think this will work, (its almost like two separate fuel systems...one mechanical, and one electronic. Both going to the same place >> the ppump), what fass adjustable fuel pump should I get (wanted to look at these fass units because they're made for diesel, have a good track record, and made in the mothereffin usa.

I know when you have a pusher pump inline such as the holley black, you want the holley set to about 14-15 psi. That way the stock lift pump ramps up the pressure from the holley and makes a nice 45-55 psi at the pump......

BUT, if its going to be a separate line and pump setup, would I want to get one that's 150 gph at 16-18 psi (like for the VP trucks)like this one:?

http://www.fassride.com/detail/diesel-fuel-pumps/adjustable-diesel-fuel-pumps/adjustable-dodge-ram-cummins/adjustable-fuel-pump-150-gph-dodge-cummins-1998-1999-2000-2001-2002-2003-2004.php

OR one that is 125 gph at 45 psi (like for the 94-98 trucks) like this one:?

http://www.fassride.com/detail/diesel-fuel-pumps/adjustable-diesel-fuel-pumps/adjustable-dodge-ram-cummins/adjustable-fuel-pump-125-gph-dodge-cummins-1994-1995-1996-1997-1998.php

Would the one thats 16-18 psi make the current 25 psi I'm seeing go to 41-43 psi? being that it'd be pushing into the injection pump along with the current 25 psi? would I want that or would I want the 125 gph one that's 45 psi, that way I would be seeing 65-67 psi at the pump? or does this math not even make any sense????

Sorry for the long post, but I've been contemplating this for while and I'd like to make it work. When I wouldn't need the fass, I could turn it off with the switch and run straight carter lift pump? Would I need to put some sort of check valve in the front feed line going to the ppump so the fuel wouldn't leak back into the fuel hose for the fass then?


Let me know your thoughts please!! Thanks fellas
 
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I would think the pumps would fight each other. The injection pump would essentially be like a tee in this scenario. One pump is pushing 45psi into the tee while the other is pushing 25psi. The 45 psi would win the battle. That is my thinking at least. Sort of like using a set of turbos meant for compounds as a true twin turbo setup.

That is all me thinking out loud but I would think the two different pressures wouldn't jive. Could do it like Will did on his junker. Have the electric pump pushing to the mechanical. Compounding the fuel pressure in a way. In his setup he has a check valve so if the electric pump fails it can still pull fuel with the mechanical by itself. If that is the case you could simply turn the electric pump on and off with a switch like you want to.
 
if that's the case, i would want the lower pressure 16 psi fass pump then eh? When I would have the fass pump turned off though, would that hurt flow to the mechanical pump? I don't want to run the electric one all the time....just when I'm ripping on it or if I take it to the track or dyno etc, but I don't want the electric one to be off and make the mechanical one not even be able to do its job like normal, as poor as it may be
 
im thinking the 150 gph pump because you can adjust the pressure from 0-75 psi. I can just slowly ramp it up until its where I want. Run it inline with the stock pump and in between the filters. Only thing I'm not certain on is the check valve that was mentioned
 
Here's what I did.

I installed a Beans sump into an inline filter, then with 1/2" hose to a Walbro 392 fuel pump. This goes into a check valve, and then is Te'ed into the factory lines before the filter. I also installed a check valve in the factory fuel line coming from the tank before the tee.

I have also installed a check valve in the factory lines before the tee, I tried it without this check valve and it only provided me with around 15 psi fuel pressure.

I put the Walbro pump on a switch so I can use when I need it, it's running around 40 PSI at idle without the pump, and around 90 PSI with it on. At WOT, it's still high pressure, around 70 psi. This is at 642 RWHP on my 98 12v, with plans to add more power soon so we'll see how it keeps up.

I have pics around here somewhere, I can post if requested.
 
if you wouldn't mind, I would appreciate it bud. I guess I'm dumb, but I don't quite understand all of the check valves that were used. In my mind, I would just put the "pusher pump," whatever that may be, inline and set the pressure, and turn it on when needed. I am not very savvy in this area though so I need to read up on this. Thanks for the info though, man
 
I'm running the exact same thing your talking about. Stock fuel system feeding the back of the pump. And from the sump to a airdog 165 to the front port on the pump with no check valve. Makes 20psi on stock system under load and 75psi with both running.
 
R1raptor said:
I'm running the exact same thing your talking about. Stock fuel system feeding the back of the pump. And from the sump to a airdog 165 to the front port on the pump with no check valve. Makes 20psi on stock system under load and 75psi with both running.
Click to expand...

do you have any more information and pictures about this setup buddy??
 
Zeppelin654 said:
if you wouldn't mind, I would appreciate it bud. I guess I'm dumb, but I don't quite understand all of the check valves that were used. In my mind, I would just put the "pusher pump," whatever that may be, inline and set the pressure, and turn it on when needed. I am not very savvy in this area though so I need to read up on this. Thanks for the info though, man
Click to expand...
This way would work and seems to be the way lots of people do it, I just did mine differently.

I am still using the entire factory fuel lines going front the tank to the mechanical pump. I also have the walbro pump from the sump with totally separate 1/2" fuel lines all the way to a tee that joins it with factory fuel line.

The reason for the check valve is that when I don't have my electric pump running, the mechanical pump would just flow up to the tee and send it right back to the tank.


Sent from my SCH-R950 using Tapatalk
 
Walbro's use a built in check valve on their 255 pumps. It's on the outlet side and can be removed. If you run them parallel it won't back feed.
 
gman99 said:
Walbro's use a built in check valve on their 255 pumps. It's on the outlet side and can be removed. If you run them parallel it won't back feed.
Click to expand...

That is really good to know. Thank you for that. Makes my gears turn now. I have a second bung in my sump and nothing in the front of my pump.

My worries were back feed issues but I may do something similar to the OP now as I had my eye on the walbro to use by itself before.
 
Put it on a pressure switch tied into the boost pressure. Once you exceed x boost, the second pump kicks on.
 
12208835_10153415312664064_2782983352472721600_n.jpg


there is a boost reference port on this pump.... :)

will fuel flow properly through the fass pump even when its not running if it is right inline?
 
Have you looked at the glacier diesel fuel boss lift pump?

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I was going to go waterman right from the get go to not have any electronics to deal with, but my front cover hit the damper, so I said bag it, and I just got a new stock lift pump.

What do you guys think my best option is?

Go DTT or glacier belt drive system and completely eliminate the stock system?

or go with a fass pusher pump on top of the stock system?
 
What's the rest of your fuel system? Pump mods? Injectors? Turbo? Where are you power wise?
 
billet 64/83/.9 T4
5x.016 155* (as per Weston's recommendation)
full cut's ( I think )
4k gsk
stock lines
20* timing
tork teck adjustable OFV maxed out (so should be 34 psi idle)
brand new carter lift pump with no fuel heater and new pre screen
hellman sump into 1/2" line to 3 micron donaldson filter into 3/8" line to 2 micron wix filter to stock metal line into ppump
no plate OR afc....(not too happy about that but this pump was from a hot street truck/puller so its what I have to work with)

I need to find a plate and possibly an afc (I've had trucks on the street without afc's before and its not too bad, but she want's to sit at 900-1000* egt during semi spirited driving and that seems too high for me)

no idea on power: maybe 500-550 to the wheels??
 
I wouldn't worry about the plate, but having an AFC would help alot with your egt's. Bringing in the fuel smoothly will make a big difference in temps while hammering it. If you have smaller injectors and DV's then the AFC makes less difference daily driving as you can't over fuel it too bad. Full cuts and 5X.016 can over fuel your motor pretty heavily before boost comes up.

I'm actually considering doing what Zstroken suggested. I used an adjustable pressure switch on my methanol setup for my procharged camaro. I had it tied to a red L.E.D. next to my boost gauge so I could see when it actually turned on during a run. Worked great and was useful for street tuning. Seems like the same theory would work well for a secondary fuel pump.
 
I like this thread. I have just a airdog 200 but dont trust it anymore(had a previous airdog leave me stranded on the side of the interstate). I wanna incorporate the stocker back in somehow so when the electric craps out I can keep going at least. plus more fuel psi at WOT would be nice
 
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