Engine/Transmission (1998.5 - 2002) Two fuel pumps near tank ( question)

[RCrosby]

For you guys that have two lift pump on frame near tank, that are only running one and has the other one for a backup. question i got is i have a fass ddrp on the frame and my old walbro 392 mounted near it also. But it is not connected to the fuel lines. Do i have to put a (check valve) are a (ball valve) between them so the fuel does not back feed threw the other pump. Like to see pic's if there is some. Thank

 

[Hammer]

Many guys I know who still have two systems on their trucks just make them a easy switch over with minor wrenches.

Most of the others like myself have just gone to the aftermarket systems totally.

 

[RCrosby]

So it seems like the best way to go is to have a pair pump ready to put on if needed.

 

[dcoffman]

I installed a FASS DDRP about 5 months ago and am very pleased. Presure is about 16lbs. idle and has never gone under 14. 5 at full throttle. I've got the old pump in my truck box just in case I,or a fellow DTC owner is on the road with no fuel pressure.

 

[AWeiman]

check the lastest issue of the tdr. pg. 67 good write up about having 2 lift pumps.

 

[Allnew2Me]

I used ball valves that prevent any back-feeding through the spare pump but you could design a system that uses a check valve instead.

check the lastest issue of the tdr. pg. 67 good write up about having 2 lift pumps.

I wrote that article and the original posting is here if you want to read it.



https://www.turbodieselregister.com...002/190424-no-more-lift-pump-troubles-me.html

 

[firefighter_2000]

Im wanting

I used ball valves that prevent any back-feeding through the spare pump but you could design a system that uses a check valve instead.









I wrote that article and the original posting is here if you want to read it.



https://www.turbodieselregister.com...002/190424-no-more-lift-pump-troubles-me.html

Im actually looking at doing the same thing to my truck soon. Your article was my inspiration. Have had it in my favorites folder for better than a year. I like the idea of having two lift pumps. Have even thought about using check valves and a dpdt switch and being able to switch between the two pumps without leaving the cab. Thanks for a great write up on the website and in the magazine.

Thanks

Craig

 

[Allnew2Me]

After thinking about what the original poster said about check valves, it occured to me that by using them instead of the ball valves I used, the system could be very simple and reliable.



It would also eliminate having to get under the truck to throw the valves. the DPDT switch could be mounted in the cab and a flip of the switch would change over to the new backup pump and automatically start the flow in that pump's system. The pressure from the active pump would force the second valve shut and direct the flow to the engine, and by switching over the new pump would do the same all automatically.



I wish I had thought of that when I did my conversion to the dual pumps, I like it even better than what I came up with. Less parts and a much easier switch-over even while driving. Genius RCrosby and firefighter.



The only issue is finding a reliable and tight-sealing check valve to use, maybe a plumbing-type flap valve?



Here is one possible schematic that I think would work, please forgive the image quality but I think you can get the idea from this. Is there any reason that this would not work?

 

[RCrosby]

Hey guys thanks for the info. I had a problem with low fuel pressure last week. It was running about 7-9 psi. That is why i wanted to have a spair pump ready. I found the problem it was the screen in the tank for the suction side it was cloged about 90%. Install a draw straw. All good know 16-18 psi. I will be installing a carter pump for back up. And have the fass pump also. Thanks