Fass system on a 12 valve questions

cetaneaddict

cetaneaddict

Causing my own headaches
Joined
Aug 2, 2012
Messages
1,281
Well I bought a used fass 150 gph hd series about 10 months ago and finally got the ambition to want to put it in. I bought the fitting kit from fass and they forgot to put install directions in. I'm just confused on doing the stock fuel filter delete, block of plate for factory lift pump and how to tie in my fuel pressure gauge. Right now my fuel pressure gauge is tied in by a torque tek fitting. Also how will the return lines from the factory be affected if they are effected by it. The rest I can do. I installed a 90 gph on my 24 valve and it was easy. Maybe I'm over thinking it. Any pictures would be greatly appreciated! I'm sure there is write ups I just can't find them. I spent alot of time on google.
Thanks,
Jesse
 
Alright so I had to make my own fuel pump block off plate, because napa, car quest, advanced auto, autozone did not have any in stock for a big block chevy. So I installed my sump, mounted my pump, ran my fuel line to my injection pump and hooked it up. I pulled the factory fuel filter canister out while I was at it. My question is how to I plump in the injector return line into my factory return line that returns into the tank? So how do I convert that banjo fitting into a barbed fitting? Because it originally dumped into the factory fuel filter canister. I can't find any write ups on installing a fass system on a 12 valve. Also what do I do with the two plugs I unplugged from the mechanical lift pump ? I'm assuming one is a fuel heater? And the other one is ???? Sorry for all of the questions I'm hoping someone can point me into the right direction. Sorry if my typing isn't the greatest I'm exhausted and have to be up for work in 4 hours.
Thanks,
Jesse
 
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I read in one of these threads a tee was acquired from napa that would accept a banjo fitting... Or am I dreaming up random sh!t again?
 
Thank you for finding the threads! I may seem like an idiot but my fat fingers spent about 3 hours Saturday trying to find fass installation directions for a 12 valve and coming up with very limited material. I love how it says tie injector return line to factory return line but doesn't tell you or show you how in the fass directions. Also I saw that fitting you showed me I don't think it will work for my application because fuel would just pour out of the bottom since my factory fuel canister is not longer there. I will try to find an m12 fitting with a male barbed end in the other side at one of my local auto parts stores and use rubber fuel line and T into my factory return line.
 
A T that would accept a banjo fitting ! Interesting, and found at napa? Even more interesting! I hope your not dreaming would make my life alot easier. I still have hacked up wiring mess I need to figure out for the fass system I have to deal with. The guy I bought it from cut the wiring harness apart for it
 
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I just Googled "fass installation manual". LOL Sometimes Google works alot faster than just looking on one part of a single forum.

Block off the old pump, zip tie the wires up, and tie into the factory return line with a piece of rubber hose and a banjo/barb fitting. Tee the injector return into that.
 
Thanks again for your help! The reason I don't have many posts on here is because I use the search button as much as possible. Then again the search button is only as smart as the operator!:doh: Only things left on this project is capping off the factory supply line and figure out the mess of hacked apart wires and relay. One of the biggest down falls in New York there aren't really any diesel performance shops to turn to for help around here.
Thanks again!
 
I plan on unhooking the return line on the back of the head and replacing it with with that fitting I linked above and running a rubber fuel line down to my factory return line and Tee into
 
You can also just cut the factory line and slide the rubber line over it. Lots cheaper.
 
Barb to barb just to be safe I only want to do it once and not have it possibly leaking in the future. I'm pretty sure it is a m14 thread according to the sticky on this topic of cummins fittings and threads. They state that at the back of the head for a 24v is an m12 thread, but no one has posted for sure at the back of a 12v head for the injector return line it is an m14 thread. I am hoping someone is Verify this 100%
 
So as of right now I am looking for a fitting with m14x1.5 on one end and a barbed fitting on the other
 
I planed on using a 5/16 tee. So I was looking for m14 female thread on one end to a 5/16 barbed end in the other, and run a 5/16 line from the injector return line to the tee that is connected to my factory return line to the tank. So I don't know what -an fitting I would need ?
 
I have just made my own fitting at work from some natural gas fittings
 

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