Engine/Transmission (1998.5 - 2002) Latest evolution of my Carter pusher pump

[Gary - K7GLD]

Tho' my added Carter pusher pump has been operating flawlessly, I had nagging concerns that the idle pressure was just a TAD higher than I liked, and the fact that if ANYTHING caused the added pusher to quit, it would immediately shut down the truck due to fuel starvation...



SOOoo, I picked up a second pump to experiment with - goals were:



1. Slightly reduced overall pressure.

2. Provide a bypass to allow stock pump to continue operating in at least a reasonable fashion until proper repairs could be made.

3. Hopefully, reduce the occasional noticeable operating noise occuring with the first pump by reducing head pressure with valving in new bypass assembly.



Here's what I ended up with:



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Here's an exploded view of the individual parts:



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Here's a closer detail of the "shadetree" bypass valve - the goal was to provide as much flow AROUND the pusher as possible in case it failed - and ALSO provide a SMALLER bypass during normal operation to bleed off a smaller percentage flow... The screw shown is a "flip-flop" arrangement that operates on fuel pressure, when the pusher operates normally, the "valve" is pushed against the internal shoulder inside the shown brass fitting - and fuel can only flow thru the drilled hole. IF the pusher fails, flow is reversed by the stock LP sucking, and the valve opens to its larger flow arrangement...



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AND, here it is installed:



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End result?



Idle pressure dropped from nearly 26 psi to 22 psi, cruise dropped from 22 psi to 20 psi - WOT dropped from 18 psi to 15 psi with my Comp set on 5x5...



Shutting down the added pusher dropped idle pressure to 15 psi - haven't tried driving it that way - but am confident it WILL operate as a satisfactory "limp home" mode - and absolutely NO operator intervention is required, it's all automatic, and used about $15 in various fittings...

 

[Riflesmith]

Gary,

Thank You for an outstanding, informative post. I had trouble on a recent trip that turned out to be a bad connection to my OEM lift pump. This shut down both pumps since my pusher is relay triggered by operation of the OEM pump. Let me assure you, there is no HP available when this happens. It is a real PITA to troubleshoot by the side of the freeway at night as well. Your setup would be a major improvement in reliability.

 

[Gary - K7GLD]

My added pusher is keyed by a relay operating off the stock pump like yours is - but it's pretty easy to determine which pump has failed, and an ordinary Radio Shack jumper wire from the battery bypassing the relay will operate the pusher down by the tank - and I always carry a few of those jumpers with alligator clips on the ends for that sort of emergency...



Of course, yer not gonna force much fuel thru a failed stock LP if it dies, either!

 

[PRout]

Hello Gary,



This is a little off the main topic, but, I was interested in getting your input on how much RF interference you get in the receive of the Icom with the new fuel pump.



Have been hearing that some Fords with noisy in-tank pumps create an RFI problem for us ham operators. Also have heard our cummins rigs arent too bad as far as radio noise goes. I haven't gone mobile with this rig yet, so dont know.



Am thinking of installing the same radio you have, with a clearspeech unit in the audio line, and maybe an SGC cube amp, or something that has 8 2sc2879's to help blast out of bad spots. Maybe a screwdriver antenna, with lots of emphasis on good grounding practices.



Anyways, was just interested in what you've found with your setup, as far as how much additional noise (if any) the pusher pump added.



Thanks for your opinions. -wb6bfd

 

[daveshoe]

Anybody else have message of IMAGE FILE NOT FOUND where pictures should be?

 

[tarussell]

Yep ! No pictures on my end ??????? Thomas

 

[Gary - K7GLD]

The pics have been restored, and should now display properly...



As to the question about RFI from the added pump, no problem - look closely to the right of the mounted pump, and you will see a donut-shaped ferrite choke wound with the lead supplying 12 vdc to the pump - and also visible is a . 01 capacitor across the power terminals to the Carter 4600... No noise of any kind...



I have another Carter pump I use to transfer fuel from my added in-bed tank...



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It's not visible in this picture, but there is also a . 01 capacitor across it's power terminal as well, and it too is totally quiet in operation...



On my truck, any frequency, any band - absoutely NO difference in backround electrical noise level whether the truck is on or off...

 

[lmills]

I've got pic's. That's a pretty neat idea. I think I will have to take some notes. Can anyone tell me the part number that most are using for the pusher pumps?

 

[JWhitcomb]

So as I understand it, you have made a one way valve that will leak a bit when the pressure changes

 

[Gary - K7GLD]

YUP - a built in leak around the pump that leaks a little in normal operation to reduce total system pressure - and a LOT in the reverse direction if the added pusher fails for any reason... WIth the added pusher disabled, I'm only down in PSI by 1 lb at idle from what it was before I added the pusher...

 

[JWhitcomb]

So the bolt just loosley fits in the hole in the brass fitting and just depends on the flat on the bolt head to press against what must be a flat bottom hole in the fitting?



Have you thought of a bypass up at the stock LP so in case of failure your pusher could just go around instead of through?

 

[Gary - K7GLD]

"So the bolt just loosley fits in the hole in the brass fitting and just depends on the flat on the bolt head to press against what must be a flat bottom hole in the fitting? "



Yes, the shown bolt fits tightly against the internal shoulder of the fitting when the pusher operates under pressure as it should, leaving only the 1/8" hole for fuel passage around the pump - good for 3-4 psi drop in system pressure - and then, if the pusher is shut down for any reason, there is SUCTION in the bypass line, and the floating bolt is pulled the opposite direction where its shoulder rests against the notches cut into the mating surface, allowing much more flow via that route in addition to the 1/8" hole drilled thru the bolt...



Works real slick - and yes, I have thought about a similar setup for the stock pusher as well - but other priorities keep getting in my way...

 

[jerryrigg]

Gary-



I really like your bypass... so much so I'm going to incorporate it into my Triple Pump No Fail system... originally I was going to use some solenoid valves and a couple manually bypasses with quick connects but I like what you have done. Sometimes I tend to over "jerryrigg" things and your setup is going to greatly simplify my plan and save some $$$$$...



I've already redesign the switches/relays... if you take a look at this (#ad
) and you'll see where I'm going...



3 Dash switches, 1 for lift pump, 1 for pusher #1 and 1 for pusher #2... .



You'll notice the SPDT relay on Pusher #2 will turn off Pusher #1 and turn on Pusher #2, the relay will also turn off the dash light for Pusher #1, I just did not add lights and filters etc to the drawing to keep it simple... all it all I will always have fuel to the VP44 and should not have to limp home. .



-Matt

 

[Gary - K7GLD]

Golly Matt - and one of the guys was asking ME if I wore both a belt AND suspenders...



If what I've shown above was a help, well glad to have done it...

 

[Idaho CTD]

Anyone try two 7psi carters?

I was just curious to see what kind of pressure they would give. It would be nice to keep it down in the upper teens and not go below 13-14 @ wot.



Nathan

 

[Gary - K7GLD]

In my book, the ideal setup would be a SINGLE, DEAD RELIABLE pump capable of 15 psi @ 75gph back near the tank, with a 10 psi regulator right at the inlet of the VP44 that returns bypassed fuel to the tank. The LP itself would incorporate the capability to allow fuel flow thru or around it if it DID die, so the VP44 would still be able to function with its own built-in LP. The goal being to maintain a CONSTANT 10 psi at the VP44 under ALL operating conditions...

 

[jerryrigg]

Ok Gary here we go again... .



""ideal setup would be a SINGLE, DEAD RELIABLE pump capable of 15 psi @ 75gph back near the tank, with a 10 psi regulator right at the inlet of the VP44 that returns bypassed fuel to the tank. The LP itself would incorporate the capability to allow fuel flow thru or around it if it DID die, so the VP44 would still be able to function with its own built-in LP. The goal being to maintain a CONSTANT 10 psi at the VP44 under ALL operating conditions""



Everyone agrees they messed up on the location of the lift pump, pulling fuel 8 ft instead of pushing it right from the tank is hard on that little pump... .



Now then if your running a single pump at the tank with a bypass do you really think the VP44 can pull it that far through the filter without problems if so then why have the lift pump in the first place... .



Unless you were to mount a small 1/2-1 gallon sealed tank after the filter. . then the VP44 has that fuel to draw on if the LP fails and with it being sealed the lift pump would keep it pressurized so put your regulator just before it... just need to add a "air bleed" setup on it and you could be in business... .



we both may be guilty of over-engineering / over-protecting things but generally my S*** don't brake!!! I keep Driving...

Another Item on my list is Dual Alternators... but that's another story



-Matt

 

[Gary - K7GLD]

Thought I'd bring this back to the top, since I've been getting quite a few PM's about adding pusher pumps, and how I made a bypass line around my pusher to guarantee continued flow even if it dies on me.



OH, and 3 years and 35,000 miles - NO fuel delivery problems to date...

 

[Gary - K7GLD]

I've been getting some Email and PM's from related info posted in other threads, so wanted to update this older thread. I want to underscore the fact that during the 50K miles I used the OEM LP and the slightly later added pusher, BOTH pumps operated flawlessly!



I have made the switch to the Walbro pump seen below ONLY to experiment with it, since there's been so much hoopla as to how great it is considered to be. I'd have absolutely NO qualms or hesitation in reinstalling the Carter that WAS at the location where the Walbro is, and returning to that system.



Later mods to my system prior to this post was removal of the bleed function in the homebrew bypasses, due to the installation and restriction of the Frantz sub-micron fuel filter that required more PSI for proper fuel flow - that thread/info is here:



https://www.turbodieselregister.com...sion/102344-frantz-fuel-filter-flow-test.html



That said, here's the latest pump setup itself - which has also been functioning flawlessly for over 5K miles to date:



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The Walbro GSL-392 is the primary fuel pump, automatically bypassed if it fails - the OEM Carter LP can be seen further up the frame, but is not connected to power unless the Walbro fails, and is also automatically bypassed - all that needs changing is a single power lead to switch from one to the other, and even THAT could easily be done with a simple power switch from inside the cab...



However, this Walbro install DID require the construction and installation of a regulator valve and return line for routing excess fuel back to the fuel tank - the actual homebrew valve delivers a steady 15 PSI, is located immediately ahead of the VP-44, and looks like this:



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A full detailed thread on construction of that valve can be seen here:



https://www.turbodieselregister.com...64-homebrew-fuel-bypass-regulator-valves.html



So far, so good!

 

[Allnew2Me]

I did the dual pumps a while back also and like the fact that I will never get stuck with a bad pump. Yours is like mine in that you have to see the fuel pressure drop to know your primary pump is going bad. I have to flip 2 valves to change my system to the backup pump, and change the power connector. Yours only requires the change of the power, that is nice. Gary, have you ever had any clogging issues with your bypass valves?



The original thread is here in case anyone is interested

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