Engine/Transmission (1998.5 - 2002) Secondary lift pump specs

[bwtufts]

Ive decided on some Mach 3 injectors and heard a lot about the need of putting a secondary lift pump and larger diameter fuel lines in line between the fuel tank and stock lift pump to keep a better supply of fuel going. After priceing these throught dieseldynamics.com ($200 for the secondary lift pump and $180 for the fuel lines) I decided there has to be a cheaper alternative to buying through them. I noticed that they were using a Carter electric fuel pump in there system and regular 3/8 in rubber fuel line. It seems like it would be cheaper to go throuh Napa or someone like that and just buy the pump and lines through them for probally half the price of diesel dynamics. If anyone is running one of these systems could you give me the part# off the carter pump? Or maybe someone knows gpm 's required and I can look up a pump that way. Any input would be great. I just can't see spending $380 for something that I could put together myself for half the price.



Thanks,

Brad

USMC

 

[NWhitney]

Carter Pusher

Here is the carter pusher that I came up with.

https://www.turbodieselregister.com/forums/showthread.php?t=114603



NOTE: I should have used a 10 micron pre filter instead of the 150 micron one that I did

 

[bwtufts]

By-pass line??

Is everyone running a by-pass line around the pusher pump in case it goes out??? Thought it was a little much when all you have to do is watch the fuel psi gague. Also, whats the best gague??? I was figuring between the filter and injector pump.





Brad

USMC

 

[R-N-R]

Running a by-pass around the frame mounted pump might enable you to limp home off the factory pump in case the frme mounted unit fails. I went cheap with standard hardware store fittings and a ball valve.

 

[Froadin]

Ok, how many people have had the lower pressure Carter pumps fail anyway? I know some people have had issues with some other pumps, but it sounds like the low pressure carter as a pusher pump is pretty reliable.

Besides, all it would take to 'limp home' on the stock lift pump would be a small piece of fuel hose.

Don't get me wrong, I like the idea of a bypass and all, but it seems like it adds a bit more stuff to the setup, and the factory lift pump doesn't get a bypass either.

 

[R-N-R]

These pumps do fail, however double pump setups seem to be lasting for people. The stock LP will pass fuel when they fail, hence so many people that find out their pump is bad when they put a gauge on. However I have read that the Carter pumps will not allow flow when they die. For less than $20 and 20 min. a bypass can be installed which enables the pump to be bypassed by moving a lever instead of roadside plumbing rework. In MI, the less roadside work the better, this stuff always happens in December... . :-laf

 

[Lsfarm]

just a piece of fuel hose

Well I agree that it should only take a few minutes and a short piece of fuel hose to bypass the pusher pump, but I guarantee when the pump goes bad you will be in your best clothes, or it will be raining or freezing rain. And it is virtually impossible to pull a line off a pusher pump without getting a bath in diesel fuel.



So it would be a lot easier to just have to reach under the truck and turn a handle to bypass the pusher.



That being said, I guess I need to get a valve and a few fittings and hook up a bypass on my truck!!.



Greg L

 

[isb360]

I've got my 4601 pump ready to go, but I could really use a comprehensive list of fittings, valves, tubing, etc that I will need to complete the job. I saw a good description with photos some time back but was wondering if anyone has a more updated/revised, etc list of parts. My third factory LP is getting squirrelly on me and I don't want to tempt the fuel pump gods.



Thanks in advance.



Tim

 

[Froadin]

Yeah, I am in need of a better setup as well, as my second lift pump is on it's way out. And I don't want to add anything that will overly complicate the system.

I know that Gary put on a bypass system that is automatic. But I would kinda like to know when one part fails.



Btw, I thought the stock lift pump (which is a carter), is the exact same as what is being used as the pusher pumps. If not, what needs to change (meaning, what part number) for the pusher pump that it would allow for fuel to flow through it like the factory lift pump does?

I would rather buy a pusher pump that allows the fuel to flow through. Obviously it's going to cause a restriction, but it should be good enough to run on 'normal' power as long as the lift pump is ok.

 

[R-N-R]

This reference page might help.

I know that Gary put on a bypass system that is automatic. But I would kinda like to know when one part fails.

You will be able to tell by your fuel pressure.

Btw, I thought the stock lift pump (which is a carter), is the exact same as what is being used as the pusher pumps. If not, what needs to change (meaning, what part number) for the pusher pump that it would allow for fuel to flow through it like the factory lift pump does?

I would rather buy a pusher pump that allows the fuel to flow through. Obviously it's going to cause a restriction, but it should be good enough to run on 'normal' power as long as the lift pump is ok.

I have wondered about the factory/aftermarket fuel flow as well. It seems that if the factory pumps "stops" in a certain position, it will block flow as well. But this certainly seems to be the rare exception. How or why this is different from the aftermarket pumps is beyond me, but for the price and time of a by-pass, I was not going to take the chance.



FWIW,

BIll

 

[Steve St.Laurent]

The stock lift pump is the same as the 4601hp Carter except for the fittings on it. Both pumps are rotary style pumps and if the rotors freezes in the right place will stop fuel flow - that is the exception rather than the rule though IMO. I had 4 stock pumps fail between 28,000 (I bought the truck with 24,000 on it) and 65,000 miles and none of them froze where fuel wouldn't flow through. At 65,000 miles I replaced the factory pump and put on a 7 psi Carter pusher in addition and ran great for years. At 150,000 miles the factory pump died (could tell by my fuel pressure gauge and unplugged each pump in turn to figure out which one it was) - it didn't stop the truck, I drove it an hour and a half to a Cummins dealer at midnight to get the replacement.



isb360 - if you are putting that pump on as a secondary lift pump to supplement the stock pump you have the wrong pump. The 4601hp is a 15 psi 100 gph pump and if you use that along with a stock pump your fuel pressures will be in the 30 psi range. The pump you want to use as a supplemental pusher pump is the 4600hp which is a 7 psi 100 gph Carter.



On the bypass I have enough rubber hose coiled on mine that if the pusher was to die where fuel wouldn't flow through it I could bypass the pump in about 2 minutes - loosen 4 hose clamps, move the line and retighten the hose clamps.

 

[isb360]

Steve,



I think I mis-typed... I did buy the 7psi pump, so it must be the 4600, but I will go double-check to be sure. I will be using it as a supplement to the existing lift pump.



I have seen set ups where the pusher comes on at "key-on", and others toggled on manually. I have heard that there is restricted pressure available to the VP during cranking and have wondered if the pusher is activated by "key-on", if that will be too much cranking pressure. Then again, I don't want to have the hassle of always remembering to toggle a switch on and off when I want the pusher to work.



R-N-R: thanks for the link, very helpful. Now I need to get added hardware to go with the pump I got from JEG's.



Suggestions?



Thx

Tim

 

[Froadin]

isb360, you can just trigger the relay for the pusher pump from the stock pump. This way they both come on at the same time. Which means for startup, they will bump on then turn off until the engine starts cranking. Gauging by the psi most people report, it shouldn't be an issue if wired like this.



I would like to know the 'odds' on the pump failing where it blocks the fuel flow. As it doesn't seem to be TOO big of a deal with the stock lift pumps, and we all know those fail all the time. Still, I would like to know the statistics on that one.

 

[KYLE4]

Check out my lift pump relocation with banjo elimination and 1/2 fuel line it is on the fuel systems page on my website.

 

[R-N-R]

I was hoping somebody would step in and explain the flow/no flow thing... . thanks Steve!



There are two styles of doing this. One is to add a pump for pump reliability. The other is to replace your fittings with high flow fittings to improve pressure/reduce stress on the pump(s). Typically, when one is replacing the fittings, they also add the 2nd pump or install a high end unit. From what I have seen, purchasing a kit will cost you about $40-$50 more than buying everything yourself, and the kit typically includes the wire harness. I expect that there is a difference in the wiring harness to move the LP to the frame verses a harness that adds a pusher to the frame. For comparing prices, make sure and add in extra for the parts that you purchase that you don't use for whatever the reason. So, the net effect is that typically a kit will cost you the same or at least be within reason of saving you the headache of figuring out what is needed. There are numerous vendors associated with the TDR that assemble these kits for us. I purchased from Olee Poole (opoole), Kyle has listed another resource as well.



However... . if you really want to source the parts yourself: McMaster-Carr is a good source, I purchased my standard plumbing from Lowes and/or Home Depot. For high flow fittings, Summit Racing Equipment is a good source.

 

[Gary - K7GLD]

For those unfamiliar with the inner workings of the stock LP, as well as the off-the-shelf Carters used as pusher pumps, check this out:



https://www.turbodieselregister.com/forums/showthread.php?t=108275



... And for at least one version of an installed, ZERO maintenance bypass arrangement:



https://www.turbodieselregister.com/forums/showthread.php?t=59880&highlight=bypass+valve

 

[isb360]

Froadin: I like the idea of tapping into the factory LP trigger (ECM controlled?) to turn on the pusher, and have heard of others doing this. Do you have any suggestions/recommendations for the best way to tap into the factory wiring to trigger the relay?



Tim

 

[Gary - K7GLD]

Froadin: I like the idea of tapping into the factory LP trigger (ECM controlled?) to turn on the pusher, and have heard of others doing this. Do you have any suggestions/recommendations for the best way to tap into the factory wiring to trigger the relay?



Tim

Cummins sells a 10 inch or so LP power extender cable that can easily be used to solder across the leads for actuating voltage for a relay coil, it simply plugs into and extends the stock LP power feed - I don't have the part number handy, someone will probably supply it for you - it sells for about $8...

 

[Froadin]

Seems to be a few ways to power the relay.

If you look at the previously provided link, they show the stock relay has an extra connection you can use just for this purpose.

https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=19040&width=0



Not sure if the stock relay has enough amperage capacity to cover both pumps, but it probably does.

You can always use that power line to trigger a seperate relay for the pusher pump though. And the relay itself takes very little power to trigger. Even a scotch lock connector on the lift pump's power wire would work. But I wouldn't use that route as you are just asking for trouble. Personally I would use the wire from the stock relay (my plan actually, I am about to put in a pusher pump, I am just deciding on the best route).



There is some nice links in this thread, it has helped me out. Thanks guys!

 

[Steve St.Laurent]

Actually, there is no "stock" relay for the lift pump. It's fed straight from the ECM. I would definately add a relay and trigger it from the existing lift pump wiring. I set mine up just like the one shown above. For the power feed I took it from the PDC box under the hood on the fused side of the input and put an inline fuse on that power lead. I scotch locked the trigger wire to the harness on the factory pump. You may or may not have a harder start if you try to start the truck while the pumps are cycling. The ECM cycles the factory pump very fast - too fast for the relay to react - so your pressures are higher at cranking than you would optimally prefer. I just wait for the pumps to shut down (takes a few seconds) and then crank and it lights off no problem - not everyone has that issue.