One Way Valve On Fuel Rail

[Shaun]

Ok so a quick one here for the group, thinking I need a OWV on my fuel rail, I have them on the LP side to stop fuel being back fed to the wrong tank, issue on the HP side is the ECU primes the fuel rail and after 10 seconds will shut the pump off which is a good thing in my book stop the pump fighting itself.
Issue I see then is the fuel pressure will drop, the HP pump only then cuts in on the starting of the engine, so I need a way of holding the HP line at the correct PSI.
Thing is I am not sure how to plumb anything is as if I put on the flow it can drop pressure via the return and vice versa
Are my Sunday ramblings making sense? I did get a OWV to fit the Bosch fuel pump but it has a banjo fitting which I am not using, mine are all AN so I did not really want to replumb and anyway I will have the same issue in that the pressure can be lost on the return side anyway.
Thoughts?

 

[JP Verweij]

Bosch O44 pumps have them allready fitted.

Normaly used with this take off kit ( capnut & banjo)

 

[Shaun]

Yep not sure mine came with one, spoke to Mick at SGT and he says not to bother never done or needed one in the past, I just dont see how it would work anyway unless the whole lot swirl pot and all was pressurised
Anyone need a OWV

 

[Ian Anderson]

Fuel injection on the DAX
NO one way valve

ian

 

[Neil]

A shuttle valve would be ideal. It has two inputs and one output. A sliding spool inside selects whichever input has the highest pressure and connects it to the output port. The lower pressure input port is then blocked. There- two fuel pumps and one output.

 

[Hans]

Maybe a little leaking spot in your fuel system

 

[JP Verweij]

When I went Injection (Megasquirt) I started without causing the same issues you described.
On advice from my Megasquirt suplier I wen't back to the one-way valve on the pump as it came with and the system stayed presurised for hours.
Way easyer startups.

Running the Bosch 044 (6.5bar pump, cheap Oriental version)
Injection rail has a 3bar Weber Marelli regular and a return on the other side of the rail.

 

[Ed McClements]

Shaun
In addition to the 10 second priming, and running the fuel pump when the engine is running, does your ECU also run the pump while cranking? That should build pressure for starting...and then you're running.
Eddy

 

[Shaun]

Cheers Eddy that's worth a check, consensus seems to be valve not required which is good news!! Bad news is I got one but they are good at returns
Now I just need to sort a non charging alternator and loads of water leaks, Mick mentioned silicon hoses are notorious for that, mine are clamped tight but drip even when engine off and cold, I use Mikalor clamps as well so darned tight!!

 

[Neil]

"...mine are clamped tight but drip even when engine off and cold, I use Mikalor clamps as well so darned tight!!"

Replace your clamps with these: https://www.amazon.com/Gates-32941-PowerGrip-Hose-Clamp/dp/B000CRDL7K

 

[JP Verweij]

I also use these Mikalor clamps all around.

 

[Bill Kearley]

Or ! I use Parker push on, special brass fittings and 300 psi hose, but like the shrink clamps, a one time use !!

 

[Shaun]

"...mine are clamped tight but drip even when engine off and cold, I use Mikalor clamps as well so darned tight!!"

Replace your clamps with these: https://www.amazon.com/Gates-32941-PowerGrip-Hose-Clamp/dp/B000CRDL7K

Never seen those bad boys!!!

 

[Bill Kearley]

Neil, are you using silicone hoses, they love to drip.

 

[Shaun]

Neil, are you using silicone hoses, they love to drip.

Bill, I sure am, there was me thinking they were better than good old rubber!!! Do they ever stop dripping?? Its the two that connect to the rad are the issue mainly

 

[Neil]

I use silicone hoses exclusively other than hard lines. Not a drop is leaking. You need to tighten the hoses uniformly around their periphery which is what the heat-shrink clamps do very well.