Engine/Transmission (1998.5 - 2002) Question/Suggestion for Pusher Pump Setup

[CoreyPerez]

Here is my proposed suggestion for the pusher pump situation.



I've been reading all about the carter pusher pumps, and the debate about the filters & high pressures when starting.



My idea is that, it seems like the pusher pump is really only needed when closer to WOT than when starting and cruising through town. I can recall a post saying that Cummins suggested that the lift pump required (of the fuel pump) required 8psi, and that any thing over was better.



Here is the actual suggestion. I believe that we all should have a fuel pressure gauge on our system, but a pusher pump is debated. Why not do a "when required" system. This can be activated in one of 3 ways.



Manual in cab toggle: If you decide you just want more fuel, fire it off.



Throttle activated: When the vehicle is at 3/4 throttle or higher, the secondary supply pump is fired off by a throttle activated micro switch which in turn supplies more fuel.



and third,



A system could be setup by a sending unit that when the system dropped to (say 6psi) the system would self support the entire fuel system. I believe that autometer would have something that would fit this operation. I don't believe it would be anything more than a low oil pressure sending unit for the auto's with a large light that warns when pressure is too low. Just hook that up to a relay and they pump would self start/shut down to meet demand.



I've also been researching all the information about elbows, banjo's as well as fuel lines. I believe I have all of my information correct. This is what I've received from Scott, a fellow TDR member:



"you will need Weber fittings and Aeroquip elbows. Both are available at either Jegs or Summit racing. These are best used with the braided SS fuel line. I used -6AN, though you can use -8AN if you desire".



At a minimum you'll need 3 Weber fittings and 3 Aeroquip elbows, a compression/-AN adapter fitting to go from the OEM hardline that exits the tank to the braided line and a suitable length of SS braided fuel line. That will take care of the inlet/outlet of the fuel filter and the inlet of the VP44 pump. Depending on if you are using the stock Carter pump, you will need 2 more Weber fittings and Aeroquip elbows for it's inlet/outlet. You will also need 4 hose ends, plus 2 more for the lift pump. The Weber fittings to are 12mmX1. 5mm. You choose the other end of the fitting, either -6AN or -8AN, depending on your fuel line size. I'm using -6AN webers and they are more than enough with a good lift pump".



Once again, I take absolutely no credit for the information presented here. This was all Scott's doing and I thank him greatly for that. If any body else has a suggestion or correction, lets hear it. I'd like to hear what has worked for others and what they would do differently. I believe that I'll be working my fuel pump here soon. I've got just over 700 miles on my truck, and I'm not looking forward to trying to resolve any fuel problems on the side of the road.



FJ40Charles has provided me with this information about the Piers Kit:



Included:

I got the kit from Piers. Included are:



1. Carter 4600 7 psi pump

2. Mounting bracket with vibration isolators

3. Mounting screws for the bracket and pump.

4. Custom wiring harness to install between factory lift pump and engine wiring harness. (no splicing necessary to hook up 2nd pump via the included relay).

5. Relay and relay wiring harness (inc. HD inline Fuse)

6. Instructions

7. 4 hose clamps

8. 3/8" npt to 3/8 brass fittings which connects to pump

9. 3/8" fuel line hose.





In closing, I'm going to attach a numerous amount of links from the TDR site that I believe would be of interest of other folks researching this same subject. If I post a direct link or picture that an individual would like to have removed of theirs, please let me know and I'll promptly remove it from this post. As I come in contact with more information, I'll promptly post part numbers and updates.



Thanks in advance,



Corey



(LATER POST)

Due to trying to keep this post all inclusive, I'm going to put some of the Aeroquip & Earls part numbers for the Fuel pump upgrade. Now, please keep in mind, as of yet, these are not exactly the correct (confermed) part numbers. If anybody CAN conferm, please do so and I'll ensure only the correct part numbers are listed. Here are what I believe are most of the part numbers, or common part numbers for our system:



Earls:

Sintered Bronze Filtering Element

EAR-230106 -6AN 27. 95

EAR-230108 -8AN 33. 95



Screen Type In-Line Fuel Filter (Flows 4-5 gpm)

EAR-230206 -6AN 28. 69

EAR-230208 -8AN 34. 69



Earl's Fuel Pressure Gauge Adapters

EAR-100192 -6AN to -6AN 8. 50

EAR-100193 -6AN to 1/4" NPT 8. 99

EAR-100194 -6AN to 3/8" NPT 8. 99

EAR-100196 -8AN to -8AN 9. 95

EAR-100197 -8AN TO 1/2" NPT 9. 95

EAR-100198 -8AN TO 3/8" NPT 9. 95



Earl's Shutoff Valves (3/8" Female NPT inlet thread 2 3/4 long)

EAR-230503 -8AN bulkhead outlet thread 28. 99



Earl's 90* Swivel-Seal (90* Bent Tube)

EAR-809106 -6AN 15. 95

EAR-809108 -8AN 20. 95



Earl's 90* Auto-Fit (90* Bent Tube) (Feed tube looks smaller)

EAR-309106 -6AN 14. 50

EAR-309108 -8AN 14. 95





Aeroquip Fittings:



90* Elbow

AER-FCM4032 -6AN 14. 95

AER-FCM4033 -8AN 17. 95





AQP Racing Hose (Full Stainless Outer Braid, compatable with most fuels, coolant & Oils. Temp Range: -55* to 300* PSI Rating: 1,000)

-6 AN Hose

AER-FCA0603 3ft. 15. 95

AER-FCA0606 6ft. 27. 95

AER-FCA0610 10ft. 44. 95

AER-FCA0615 15ft. 65. 95

AER-FCA0620 20ft. 87. 98



-8AN Hose

AER-FCA0803 3ft. 17. 95

AER-FCA0806 6ft. 32. 95

AER-FCA0810 10ft. 54. 95

AER-FCA0815 15ft. 79. 95

AER-FCA0820 20ft. 105. 9



Aeroquip AN Flare Adapters

Flare Union:

AER-FCM2052 -6AN 4. 25

AER-FCM2053 -8AN 6. 25



Union Reducer:

AER-FCM2156 -6 to -4AN 4. 95

AER-FCM2160 -8 to -6AN 6. 95

AER-FCM2163 -10 to -8AN 10. 50





Locknuts:

AER-FCM2072 -6AN 5. 25 (pack of 2)

AER-FCM2003 -8AN 5. 25 ea



Part Numbers:

Carter P4601HP (15-18psi) Carter P4600HP (7psi)



Threads:



[URL=https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=19767[/URL]

[URL=https://www.turbodieselregister.com/forums/showthread.php?threadid=53888&highlight=Pusher+Pumps[/URL]

[URL=https://www.turbodieselregister.com/forums/showthread.php?threadid=53629&highlight=Pusher+Pumps[/URL]



Fuel Pump Kits:

[URL=http://www.smokindiesel.com/Dodge/24_valve/fuel_system_24v.htm]smokin diesel's fuel pump kit

Piers Diesel Kit (aux. pump)

Enterprise Diesel





Pictures from misc. TDR Members:

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(RADdodge's Pictures)



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[emjay]

I like the throttle-activated switch idea, but with an added twist: a parallel lift pump that is actuated at 3/4 or whatever throttle, backed up by a pressure switch to turn it on whenever a preset low pressure threshold is encountered by the full time pump. As long as there's enough inlet volume, that might be an excellent backup system. Anybody done that before?



P. S. Excellent idea, and well done post.

 

[Steve St.Laurent]

The problem with that is it only takes care of one of the two concerns with the lift pumps as I see it. My reasons for going to a pusher pump setup were:



1. to increase the reliability and longevity of the fuel supply system - on my truck I replaced 4 lift pumps between 28,000 and 60,000 miles - put a pusher pump on and at 108,000 I'm still on the same two pumps with no degradation in performance



2. to maintain pressure at the VP44 under WOT conditions - when I put the pusher pump on my truck we had no WOT spec to go by and the goal we had at the time was to maintain anything above 0 psi.



JMHO

 

[emjay]

Agreed. But in the event of either the lift pump or pusher pump failing, the fuel supply is stopped if the pumps are in series. If the pumps are in parallel, there are at least two distinct advantages:



1. The secondary pump, which does not see constant use, can supply fuel in the event of a primary pump failure. An indicator lamp on the dash could alert the driver to this condition.



2. Volume is doubled (neglecting the effect of inlet restrictions)when both pumps are running, which should keep the pressure up.



I'm not trying to start a war here, just thinking out loud.



Has anyone tried using an oil cooler with a fan to cool the fuel in the return line?

 

[Gary - K7GLD]

"Has anyone tried using an oil cooler with a fan to cool the fuel in the return line?"



I suggested it while I was involved in installing my own pusher - others have prpbably discussed it as well. We pretty well know that the return fuel from the injector pump gets heated - but no real numbers I am aware of as to how hot it actually gets, and what effect that heat really has on the overall fuel system... The heat MIGHT be bad in the summer - could be GOOD in the winter - and then of course, the level of fuel remaining in the tank undoubtedly provides some significant degree of control/stabilization to heat soaking - at least until it's allowed to get too low...

 

[RADdodge]

Can't Keep My Mouth Shut...

Corey – Excellent post, you obviously have given a lot of time and thought about this. I agree completely in that I'm not looking forward to trying to resolve any fuel problems on the side of the road either.



I think most members want to know what they can do to protect their investment in their truck and what is the least expensive way to accomplish that. I agree with Steve in that the first priority was/is to improve the reliability of the lift pump system (so the injection pump lives a long healthy life). Since the VP-44 can only pump so much fuel, all the other components will be happy if the VP-44 gets what it wants. I figured about 45 gph would be good enough, but subsequent information suggests that number may be a little low for a highly BOMBed Cummins It appears that the Carter is sufficient to deliver any amount of fuel that the injection pump needs, IF the lift pump is working properly. All the other enhancements provide a lot less result for the money spent, but hey, they really look good. I would like to do the braided SS lines and fittings someday too…



I like the idea of using a dynamic system to increase the pressure at WOT. (BTWIAC - anything above 0 psi is enough to satisfy the injection pump and 0 is enough if you really know it is only 0 and not suction. I know a positive reading makes us all feel better!) I would like to see someone try it. I think it might add to the complexity of the system and increases cost. . But one never knows until someone tries it.



I also like the idea of a parallel lift pump system, but both would need to be mounted by the fuel pump. I still favor the pusher pump concept because it seemed to provide the most insurance for the least cost. I do think it is prudent installing a fuel filter in front of the pusher pump.



Currently my thinking is that it might be a better set-up using a pusher pump (with a fuel filter), and also replacing the stock 15 psi pump with a 7 psi one. Performance should be good (gph). If one fails, you can get somewhere to get it fixed without ruining your injection pump. And the lower psi (around 12 psi at idle) should allay the fears that too much pressure might be bad for the long-term health of the VP-44. But one never knows until someone tries it.



P. s. emjay – (you posted before I submitted my post) about the “event of either the lift pump or pusher pump failing, the fuel supply is stopped if the pumps are in series”: I understood that the Carter could pump through when dead. But I wasn’t taking any chances on my install. I used a Racor check valve to allow the fuel to flow past the pusher pump if it isn’t pushing. It is absolutely true that it works and works well. From my pressure gauge readings, there is no discernable difference between the lift pump pressure pulling from the tank directly or pulling “around” a dead pusher pump. That was one of my first tests. Originally, I used to leave the pusher pump off because I thought 20 psi at idle was a bit much. FYI.



Hey, cooling the fuel is a good idea.

 

[CoreyPerez]

I have dug out my latest Summit Racing Cataloge. I've reposted on my first post some of the part numbers as to try and help with a search about the Aeroquip & misc. fittings/braided hose.



I really appricate all the positive input. As far as an fuel cooler, I used a B&M trans cooler on my 88K5 Blazer and it knocked down the numbers quite a bit. I believe that we could put a bypass around it for winter use if required. I'll put those part numbers in also



Corey

 

[emjay]

Re: fuel cooling

You could use a thermostatic bypass like the one used for the transmission cooler maybe OR... .



How 'bout this (falls into the exotic category, I'm sure, but I'll toss it out for discussion if anyone's interested anyway):



A small aluminum manifold with a peltier device on it with a thermostat that cools it if it's too hot, or warms it if it's too cold?



For those who don't know what a peltier (PEL-tee-yay) device is, it is a solid state heat pump that, when electrical current passes through it, one side gets cold and the other side gets hot. If you reverse the + and - connections the opposite happens -- the side that was cold gets hot and vice versa. As long as there is a heat sink on it, the cold side stays cold. It's most common use I believe is those little cooler/heaters used for food.

 

[Huff N Puff]

Hi Corey,Had been thinking about a dual pumping system myself,with a second pump working only when you need it,to control over pressureizing the VP44. The problem though is when the second pump is off the first pump fuel is pulling through the second pump resritricting the suction line. I'm running 2 pumps now in series the pressure was too high for my liking so I slowed the second pump down by installing a 3ohm 50watt resistor in the power supply line from the relay to pump. The pressure droped from 26lbs to 20lbs at idle. System seems to be working pretty well so far. Merv. P. S. warning the resistor gets hot so be careful with where you mount it.