Closed loop is giving me fits. It is..

[ORCoaster]

Blowing the little rubber return lines off the injectors and diesel or WVO is going everywhere.  Not going to get better mileage doing that. 

Does routing the outflow of the IP really introduce that much pressure back into the pump that there would be enough pressure to pop off the hoses?  I replaced or cut the ends off those that were long enough and I think I have them tight but I am not sure that is going to work when the car is cruising along at 65.  then the IP generates between 63 and 80 lbs.  If I am popping the hoses off at idle I seriously doubt they will take those higher pressures.

Anyone running a closed loop return with success? 

I may need new hose altogether.  I found one broken fairly far down from the nipple.  Might explain why I was seeing MPG drops.  And occasional spots on the ground. 

What I don't understand is why I haven't had a problem until I switched it to the closed loop system to purge the IP.  I have had the car wrapped up on extended grades plenty and the IP pressure has touched 100 on the gauge just recently.

Let me know your thoughts.  DAS

[Wayland]

Years ago, when I converted a Rabbit to WVO I ran a looped system with no trouble. If it's just looped back to your feed line form the tank there shouldn't be any way for it to build pressure. Sounds like you must have a restriction in your return line somewhere.

[745 turbogreasel]

^ this
I ran thousands of miles looped, on diesel and  WVO.
If you close the purge line, and forget to open the loop return, the hoses blow off.

[ORCoaster]

Well, I thought I had it right and the solenoids were working as far as I know.  Might be time to run some ATF as the WVO side and see what is going on with some clear lines and a recirculation can.

I did have to switch the solenoids around a bit to get alignment right for the in and out of the diesel.  Maybe the fuel coming out the OUT banjo is hitting the wrong side of the valve body and is not flowing through but backing up instead.  

I will keep hunting down the works.
DAS

Edit after searching and turning brain on or off?   Why I had it in my mind that the return flow from the IP had to be after the main valve I don't know.  Something about replacing the WVO with diesel through consumption rather than back flushing the WVO side for the few minutes it would take to get it out of the IP and get diesel in.  Anyway I think if I go back to the way I had it, with a tee just before the main fuel selector side that will take care of my problems. 

Then when I am in purge mode the diesel is coming into the pump and has no place to go but back down into the WVO lines and FPHE.  That might mean I get a little diesel in the works but better that than sending the WVO to the main diesel tank.  I just need to know about how long that flushing will take.  My guess at idle I would move the contents of the IP and the lines in roughly a couple of minutes.  So at 40 mph and in fourth gear less than a minute? 

[mtrans]

When I try clear vinyl for air it broke to,but after I put real tube no problemo.When I drove on oil I mostly use loop all the time,I use my only one electric valve to bypass sometime to oil tank or air purge.
On idle if I do FULL purge I need ~ 2 min.

[ORCoaster]

2 minutes is about what I was thinking.  Could set it up on a timer and have it kick off automatically if I wanted too.

[8v-of-fury]

Well how much fluid can the pump hold? Quite a bit, IIRC something like one half liter or more. From previous tests of my own it took forever to idle through 100ml of fuel. And an eternity to run through my 1L fuel bottle that I was using for a controlled test fuel tank.

[theman53]

Well how much fluid can the pump hold? Quite a bit, IIRC something like one half liter or more. From previous tests of my own it took forever to idle through 100ml of fuel. And an eternity to run through my 1L fuel bottle that I was using for a controlled test fuel tank.

But the return. Giles said something crazy like the return flows a .5L per minute or something on a healthy pump, that is when mine was giving me fits and I had a bottle hooked up and it wasn't returning near that much.

[8v-of-fury]

Lol. my bad, yes it does return something stupid amount to the tank.. I forgets

[R.O.R-2.0]

Well how much fluid can the pump hold? Quite a bit, IIRC something like one half liter or more. From previous tests of my own it took forever to idle through 100ml of fuel. And an eternity to run through my 1L fuel bottle that I was using for a controlled test fuel tank.

But the return. Giles said something crazy like the return flows a .5L per minute or something on a healthy pump, that is when mine was giving me fits and I had a bottle hooked up and it wasn't returning near that much.

the pump does something like 12-15gph...

so, not much!

[8v-of-fury]

Well how much fluid can the pump hold? Quite a bit, IIRC something like one half liter or more. From previous tests of my own it took forever to idle through 100ml of fuel. And an eternity to run through my 1L fuel bottle that I was using for a controlled test fuel tank.

But the return. Giles said something crazy like the return flows a .5L per minute or something on a healthy pump, that is when mine was giving me fits and I had a bottle hooked up and it wasn't returning near that much.

the pump does something like 12-15gph...

so, not much!

.225gpm interesting.

[ORCoaster]

What were the late Hagar's specs on the outflow.  He said if at idle it should crank out something like 600 ml in 90 Seconds?  Wait let me go look, I had all his specs on a Word document and it might be on this laptop or the other computer up north. 

Hagarisms:
Pressure in pump MUST be 43.5 Psig at 1000 RPM engine,  and then this one
" If the IP flow is less than about 25 litres per hour at idle ---you will never get to really great Smileage."

14 US fluid ounces = 414.029414 ml per minute.  414ml/min X 1.5 min = 615 ml

[theman53]

You forgot the use of EH

...and *editing my own comment before posting something about a dead guy*

other than that sounds like something he would have posted.

[745 turbogreasel]

I use one 3 port fuel select valve, a manual ball valve to open or close the return loop, and another manual ball valve I can open to purge into an oil  bottle tucked behind the battery if I need to bleed.
Switch a mile or two from home, and never had issues.

[ORCoaster]

Well, I put it back the way it was and of course it still has issues.  Once weak always weak is the lesson here. 

The excessive pressure that was popping the injector return hoses off is no longer present but the fact that the nipples are lubed and the hoses weak cost me some fuel on the trip up.  I think one went to leaking the last hour of my ride.  I have several sustained grades to pull and the Bio Diesel I am running is not as peppy as the regular stuff so I have to drop a gear, or two, and wind it up.  That gives me internal IP pressures near or slightly above the 100 PSI mark. 

So perhaps the thicker fuel is going to cause me to reduce the IP pump pressure by tapping back down on the regualtor.  It is also sending me to the store for new line as I hate the mess it is making all over my newly installed stuff.  Dang it Jim! 

Hoping to get this sorted out ASAP but time is short and patienace even less.
DAS