Electric fuel pump to prime carbs

[bavbob]

Dan, happy to supply a photo. I have mine set up identical to the schematic Dick included in one of his posts. It fit in without issues despite the additional lines. I believe I ground down the edges of the one way valve so the board that goes over the tank would fit properly. I have had zero issues.

 

[Dan Wood]

Dan, happy to supply a photo. I have mine set up identical to the schematic Dick included in one of his posts. It fit in without issues despite the additional lines. I believe I ground down the edges of the one way valve so the board that goes over the tank would fit properly. I have had zero issues.

Rob
Please post what you have. I am looking for options.
Thx, Dan

 

[JFENG]

 

[HB Chris]

In my NK I have the anti-back flow valve in the engine bay and not parallel to the priming pump in the trunk.

 

[JFENG]

anti-back flow valve in the engine bay and not parallel to the priming pump in the trunk

Chris,
For some reason, your mechanical pump is able to draw fuel thru the electric pump and BavBob's isn't.
I have no idea why it works for you when the instructions for the pump say it shouldn't.
I guess it's better to be lucky.

Dan, that this happened only once is odd. But, now that you know how to resolve it I guess there's little reason to put in the bypass line and check-valve.

John

 

[Dan Wood]

This was the first time I had fuel starvation from the Pierburg without the check valve in maybe 40 starts.

 

[bavbob]

Here is my setup. Recall my car was impossible to start after sitting for a few days and the primer pump run off the defrost switch made a big difference. The first real drive I had, the car dies after about 1/2 mile from the house. That was with the Pierberg in series like Chris has. I then switched to match the diagram above and have had no issues.

 

[Dick Steinkamp]

Update on the Pierburg pump. As @JFENG predicted, yesterday after starting the car and driving about 1/8 mile, it had fuel starvation. This is the first time since adding the electric pump. Powering the electric pump got it started again and no issues after that. I believe that if I can get past that initial distance after start up, it won't starve again. Not sure I want to go with @bavbob "Roman Aqueduct system" or seeing if @Dick Steinkamp larger diameter pump will fit. I am considering options including staying with what I have.

Dan,
I don't get it. When the car starts, the fuel bowls are filled almost immediately by the mechanical pump if not already filled by the electric (if using it for prestart). I don't see how a fuel starvation event can occur after driving 1/8 mile. What am I missing?

EDIT. Is there a chance the Pierburg pump stops at a point that will not allow draw through by the mechanical pump, but 99% of the time does not stop in that position?

 

[Dan Wood]

EDIT. Is there a chance the Pierburg pump stops at a point that will not allow draw through by the mechanical pump, but 99% of the time does not stop in that position?

I suspect that is what happened as @JFENG mentions.
I ordered on of the Amazon pump that you are using in the E3. It appears I have enough room. If it doesn't work, I will use it in the 77 Wagoneer that also evaporates fuel from the carb bowl.

 

[JFENG]

chance the Pierburg pump stops at a point that will not allow draw through

That was my theory, which is possible with a cane type pump.