Partial Looped Return on an IDI

[mankypro]

I'm considering doing a partial looped return on my IDI to aid in purging while avoid the air in fuel line issues. The question is where is the best place to put said T in the lines.

Anyone that has an opinion on this please chime in.

I'm also thinking of putting a marine bulb pump in line between my lift pump and the FPHE to aid in purging air from the system and sparing the starter. sh I may just but a valve in place of the schrader at the fuel filter...

And another question, when looping returns do people eliminate the partial return to the fuel filter from the injector return lines? My truck has a T into the fuel filter from the front of the engine.

 

[mankypro]

Well, tonight I plumbed a partial return on my IDI 6.9l. Well, let's just say that I re-plumbed it back to stock a couple of hours later.

I also used some clear vinyl hose to watch for air. I had dropped my rear tank earlier and emptied it so there was clearly going to be some air in the lines.

What I did was to connect the return off the IP into a brass T into the line from my FPHE to my fuel filter.

Not good, almost impossible to get air out of the system when it seems to get trapped in a loop. I watched the bubbles go round and round. I bled the schrader valve on the filter head more times than I could count to no avail.

I'm going to try and T my veg return behind my pollack this weekend and see what happens. The only reason I'm doing this is to attempt to shorten my purge times.

Any ideas on looping for me?

 

[mcbg]

Well, tonight I plumbed a partial return on my IDI 6.9l. Well, let's just say that I re-plumbed it back to stock a couple of hours later.

I also used some clear vinyl hose to watch for air. I had dropped my rear tank earlier and emptied it so there was clearly going to be some air in the lines.

What I did was to connect the return off the IP into a brass T into the line from my FPHE to my fuel filter.

Not good, almost impossible to get air out of the system when it seems to get trapped in a loop. I watched the bubbles go round and round. I bled the schrader valve on the filter head more times than I could count to no avail.

I'm going to try and T my veg return behind my pollack this weekend and see what happens. The only reason I'm doing this is to attempt to shorten my purge times.

Any ideas on looping for me?

doesnt looping increase the chance to get air into the injectors or ip?

you can move the tank selector valve under the hood so its closer to the ip- if you do remove the plastic fuel lines and replace it with 1 long 3/8 hose

 

[bbressler]

I'm looping on the back side of the pollack. 'If you loop engine side of it, you'll trap air. If you only loop the VO line before the pollack, you can purge via the stock return back to the front tank.

But -- looping will have no effect on your purge time. There's two ways you can do that.

1. Move your pollack forward as much as possible. This shortens the amount of fuel in the shared lines.
2. Decrease the volume of your stock fuel filter housing... (For the powerstroke, they make an aluminum slug that drops in so you eliminate about 90% of the volume in the filter housing). I'm not familiar with your IDI fuel filter setup, so I'm not sure if you can do something similar or not...

 

[hheynow]

1. Move your pollack forward as much as possible. This shortens the amount of fuel in the shared lines.
2. Decrease the volume of your stock fuel filter housing... (For the powerstroke, they make an aluminum slug that drops in so you eliminate about 90% of the volume in the filter housing). I'm not familiar with your IDI fuel filter setup, so I'm not sure if you can do something similar or not...

+1
In addition to shortening the purge time, the other benefit is less cross contamination of WVO/WMO in the diesel tank every time you flip back.

I'm looping on the back side of the Pollak too.