diy e fuel questions

I did quite a bit of poking on the forums last night on diy fuel systems on the obs trucks, I under stand the purpose and what not but there were some questions that I had but no answers. So I'm posting here

1) I've seen where people utilized the factory banjo bolt and some that up graded the lines With a y block. Is there a benefit of running 3/8ths lines feeding the head/return from the head?

2) wiring I get the jist of a relay and KO power fuse, why do some people run it inline with the oil pressure switch?

3) plumbing- the feed side of the pump ( outlet to motor) goes to the feed of the selector switch, the line you just took off the selector switch goes to inlet/ suction side of the fuel pump? Am I understanding correctly? Where can I find the quick disconnect fittings to adapt to push lock hose? What sized fittings do I need for the head? ( 1/4 npt) 90* and 45*?? With a SD pump what size injectors could it fuel?

4) diagram's- does anyone have a good labeled picture of the fuel lines in the valley and on the selector switch?

At what size injector do you need to upgrade hpop's? 180cc?

Upgrade on hpop has no real set cc.... it's all about tunning and the style of injector and the plans for the truck.

On thr efuel, removing the banjo and the rear fitting removes any leak prone fitting from your fuel system

#2 answer, it's a pain not having fuel pressure when trying to start. But the reason for running a fuel pressure sensor that closes and allows current to run through it, is so if you get in an accident, your fuel pump won't keep pumping fuel.

#3 answer- if your going to use the stock selector valve, don't go above stage 2's. There are 2 inlets and returns on the valve that go to each tank. Leave the lines that go to the selector valve alone. Your gonna need to put the pump after the selector valve. The supply line should be bigger than the return line. But your also gonna need a filter before the pump to protect the pump.

I would recommend getting a painless wiring pump kit to run the pump.

http://m.ebay.com/itm/221468313592?nav=SEARCH

1- probably not as the factory head has a 1/8npt passage
2- turns off fuel when engine is not running, I have dieselsites timer to prime it (runs pump for 20sec when key is switched on)
3- pump goes between selector and engine usually
4- google

blackcloudpsd03 said:

I did quite a bit of poking on the forums last night on diy fuel systems on the obs trucks, I under stand the purpose and what not but there were some questions that I had but no answers. So I'm posting here

1) I've seen where people utilized the factory banjo bolt and some that up graded the lines With a y block. Is there a benefit of running 3/8ths lines feeding the head/return from the head?

2) wiring I get the jist of a relay and KO power fuse, why do some people run it inline with the oil pressure switch?

3) plumbing- the feed side of the pump ( outlet to motor) goes to the feed of the selector switch, the line you just took off the selector switch goes to inlet/ suction side of the fuel pump? Am I understanding correctly? Where can I find the quick disconnect fittings to adapt to push lock hose? What sized fittings do I need for the head? ( 1/4 npt) 90* and 45*?? With a SD pump what size injectors could it fuel?

4) diagram's- does anyone have a good labeled picture of the fuel lines in the valley and on the selector switch?

Click to expand...

You got a link for the timer?

2) You can run 3/8" line if you modify or buy a modified fuel rail plug. If you buy one then it has an 06-AN tit on it so you can attach a AN-06 female hose fitting to it. Diesel Innovations sells the adapted fuel rail fitting. You need one for each head for the supply side fuel connection. The internal size of the fuel rail through the head is over 7/16" diameter. Its more limited by how much you can bore the fuel rail fitting.

If you make it, then bore a hole through the fuel rail plug. Then get a AN-06 male fitting to a 1/4" NPT fitting and cut off the NPT end. Then braze the AN-06 part to the bored fuel rail fitting. Drill the hole in the AN section to match the bore size through the fuel rail plug. Probably done easiest using a lathe so everything is concentric.

Aeroquip makes the close radius bend fittings that clear the firewall, the wide sweep bends do not clear the firewall. I used the red/metal colored steel ones since the aluminum ones tend to crush when tightening in the confined space between the head and the firewall. Aeroquip also seems to have the largest internal bore size compared to the other brand's AN fittings. Russel is close, Earl's is the worst. Summit Racing has them except they special ordered the steel fittings for me.

Swamps does not reccomend using the cast 90* fittings because they do not flow as well as the bend fittings of the same size.

Magnum PD said:

You got a link for the timer?

Click to expand...

I was wrong/ its strictly/driven
https://www.strictlydiesel.com/p-2803-obs-fuel-pump-controller.aspx

I don't think the fuel rail fittings are gonna be needed in his application, and honestly I don't think they are needed untill you hit LARGE hybrids.

blackcloudpsd03 said:

I did quite a bit of poking on the forums last night on diy fuel systems on the obs trucks, I under stand the purpose and what not but there were some questions that I had but no answers. So I'm posting here

1) I've seen where people utilized the factory banjo bolt and some that up graded the lines With a y block. Is there a benefit of running 3/8ths lines feeding the head/return from the head?

2) wiring I get the jist of a relay and KO power fuse, why do some people run it inline with the oil pressure switch?

3) plumbing- the feed side of the pump ( outlet to motor) goes to the feed of the selector switch, the line you just took off the selector switch goes to inlet/ suction side of the fuel pump? Am I understanding correctly? Where can I find the quick disconnect fittings to adapt to push lock hose? What sized fittings do I need for the head? ( 1/4 npt) 90* and 45*?? With a SD pump what size injectors could it fuel?

4) diagram's- does anyone have a good labeled picture of the fuel lines in the valley and on the selector switch?

Click to expand...

#1

I was going to use the factory banjo and bought the fittings. As I started to assemble all the fittings, I decided against it. Too many fittings and it turned out to be in the way of something (I forgot). Just use a "Y" fitting.

#2

I used one of the NO/NC oil pressure sensors. The NO portion of the sensor crapped out. The 7.3 injectors create a suction and will draw there own fuel. Currently running the pump with just a relay with KO power. I wreck the truck bad enough that it needs to kill the fuel pump, I have more severe issue to worry about. Plus, I can turn the key off to stop the fuel pump. Key on power came from the old fuel heater wire.

#3

I plumbed my filters/pump after the selector valve and re-fed the 3/8 factory line. The head fittings are 1/8 NPT to -6AN straight. You can re-use the factory return hoses (-4AN) coming off the front of the heads if you mount the regulator by the HPOP reservoir. I used AN fittings/hose as I supply of them from my race car. I covered my hoses with firesleeve as precaution.

I'm running 175/80s with a SD pump. I have no drop in fuel pressure.







Billy T.
[email protected]

Thank you for all the info. I really like the painless wiring kit. I may just do that

The first picture you posted is the feed to the motor? How does it not blow off with just the hose clamps so you basically butt connected the power wire from the fuel heater to the fuel pump? Do it not not draw too much?

There is a ridge on the hard line. I have it clamped before/after the ridge. You can see the ridge on the top return line by the end of the hose.

Yes, it's the feed. You need to confirm the placement of the line. The feed is 3/8 and the return is 5/16..

I used the SD fuel pump. I found the matching connector for the fuel pump. The fuel heater wire controls the coil side of the relay, key on power. You then run a 20A line to the fuel pump off the relay.

Billy T.
[email protected]

Magnum PD said:

I would recommend getting a painless wiring pump kit to run the pump.

http://m.ebay.com/itm/221468313592?nav=SEARCH

Click to expand...

Have you/are currently using this kit?

idshred said:

Have you/are currently using this kit?

Click to expand...

that is not $40 worth of parts.
any auto parts house will have that junk

It's what I'm using. It was together, didn't break the bank.

I did order the pump controller. Thanks for the link.

I hope you dont use the butt connectors. at least pull the plastic junk off them and solder and shrink tube the connections

Never tried to solder connectors that were meant to be crimped