Adding an electric fuel pump (4 Viewers)

[RufusTheDufus]

On my recent 9,500 mile trip to Baja from Maine I noticed a slight difference in engine power between the back fuel tank and the front fuel tank when the back tank was more than 50% empty. It took me a while to notice it but I did switch back and forth between tanks while driving at highway speeds to confirm there was a difference.

I think the long length of hose and tube from the back tank in the Troopy might be too much for the stock lift pump mounted on the injection pump. I also have an inline fuel filter at the tank and the fuel tank switch too.

So I'm thinking about installing an electric fuel pump for the rear tank. I assume it should be a very low pressure unit typically used on gas engines with carburetors. Anyone have recommendations or links to the pumps they have used?

 

[70sguy]

I use Walbro FRB-5 pumps on all my 1HD-T 80 series swaps IIRC FRB-5 is 8-11 PSI at 100% restriction, so it's generally lower than that depending on the throttle position. Also the rotary pumps return fuel which lowers the pressure build up in the fuel system.
3B returns no fuel to the tank so you may want a lower PSI pump. Best to consult a Fuel injection tech to see what the implications of feeding an inline pump with low pressure pusher is.

Auto Performance Engineering - Walbro fuel pumps and more

 

[bj74redrider]

I've been using a 24V Carter unit for my 13bt and have been happy. It's a bit noisy buy tolerable. max psi is 6. You can use filters to lower the pressure if you like.

Carter Universal Rotary Vane Electric Fuel Pump P4603HD - eBay (item 330538845701 end time Mar-18-11 01:13:13 PDT)

 

[Tapage]

did you have rear tank vent ?

 

[gerg]

Check if there is significant suction at half tank. Mine doesn't vent well and creates a partial vacuum when the tank is low.
g

 

[RufusTheDufus]

I do have both tanks vented in the same manner to the fill tube near the cap. They both use 3/8" fuel hose. Maybe the back one is pinched. I'll check that today after I get the roof rack off of it so it fits in the garage.

I'll check the inline filter at the tank too. That might be partially plugged up due to poor quality fuel in some spots in Baja.

 

[Dave 2000]

I use Walbro FRB-5 pumps on all my 1HD-T 80 series

May I ask why? I have often heard this helped with the performance and wondered if it was a worthwhile job.

I have an https://forum.ih8mud.com/diesel-tech-24-volts-systems/371858-odd-idle.html

and wondered if it was related to the lift pump ageing, I checked it out with a injection specialist and he said the problem was governor related but the cost of repair was not worth it unless it got worse, fortunately it has not.

I tried a pusher pump and it made no difference to the idle or how the engine run but I wondered if it might be useful in reducing wear?

your opinon please?

regards

Dave

 

[canucksafari]

If your lift pump is working fine and if you haven't added restriction like additional filters, you will not notice a change in performance. It is considered useful on reducing wear on rotary injector lift pumps. If placed near the fuel tank (pusher pump), it also help to easily bleed the fuel system, and to detect leaks and to help prevent air from being drawn into the fuel system from small cracks.

 

[Dave 2000]

If your lift pump is working fine and if you haven't added restriction like additional filters, you will not notice a change in performance. It is considered useful on reducing wear on rotary injector lift pumps. If placed near the fuel tank (pusher pump), it also help to easily bleed the fuel system, and to detect leaks and to help prevent air from being drawn into the fuel system from small cracks.

Yep thanks for that, I was aware of the advantages but was wondering about reducing wear long term?

I may just fit one as a 'helper' anyway, at the moment though I am going through the import process to get the car registered and inspected.

thanks again

regards

Dave

 

[canucksafari]

Yep thanks for that, I was aware of the advantages but was wondering about reducing wear long term?

The assumption on various diesel forums is that it will help reduce wear in the IP's lift pump. However, I have never seen a study to prove this is true. IMO, it is possible cheap insurance that comes with other real benefits.

 

[haryv]

come to think about it, our military helicopters required to have there boost pumps on over 5,000 feet altitude. The theory is that atmospheric pressure is not enough to force the fuel from the tank and into the engine by one fuel pump. On one flight, the Flight engineer forgot to turn on the fuel boost pumps and as soon as the helicopter was flying over the base dump, both jet engines flamed out. It did a controlled crash into the land fill with minimal damage. So I do not think it would hurt to have a boost pump in the line or in the tank to help out the injection pump at high altitudes.