i have the scoop on the lift pump problem

[Mopar-muscle]

i just got off the phone with the tech line at federal mogul/carter . the lift pump that is bolted to the engine is working as designed and is designed to RUN CONTINUIOUSLY at max pressure . the problem is 2 fold , again both are poor designs by DC #ad
.

the first problem is pump location , they told me is must be NO MORE THAN 3 FEET from the fuel source . i figure there is 5 to 6 ft of line between the tank and the pump . EDIT ... . i looked under a ram tonite , its more like 8 feet ... second is the restriction caused by the banjo bolts , they are barely ok for stock HP levels , but once you go above that all bets are off .

i asked about running pumps in series, he told me that would be a good idea , but to use the HP 7 psi pump to feed the stock pump , also my thought of limiting the supply voltage is hurting the pump motor , this is not the case , he said it just limits flow and is not hurting anything .

here's is what i propose , 1) eliminate the banjo bolts and fittings in the entire system and replace the lines . 2) leave the stock pump as is in its stock location with factory power . 3) get the carter P4600HP 100gph,7psi pump , locate it within 3 feet of the pickup , actually with 3 feet of the bottom of the tank , and feed the stock pump , according to carter the factory pump will not suck the line between the 2 pumps dry .

the P4600HP pump is only 70 bucks and is rebuildable .

[This message has been edited by Mopar-muscle (edited 03-14-2001). ]

 

[illflem]

Why even leave the stock pump in there?Just one more thing to go wrong. Why not use just one pump?Another problem that has been discovered with 12 valves when using an electric pump located near the tank is that the fuel heater leaks,it was not designed for pressure just suction. The 12 valves run at 22 psi a little higher than the 24s,but not that much. The leakage actually comes out the electrical connecter.

[This message has been edited by illflem (edited 03-13-2001). ]

 

[HeberRam]

Mopar-Muscle... . Just need your thoughts? If the lift pumps, are poorly designed, because of location and banjo fittings, would poor lift pumps cause the injection pump to fail?? Do you think larger injectors, fueling boxes, have caused these lift pumps and injector pumps to fail???

 

[Evan A. Beck]

Mopar, I have installed the same setup with the dual pumps. I left the stock pump in its location, and added the Carter pump on the side of the left frame rail. I did it on a 2000 Ram that was on its third lift pump. Fuel pressure was excellent, never went below 11 psi, and that was under heavy load. At idle, it was at 19-20 psi. Email me if you need any additional information. #ad

 

[Mopar-muscle]

illflem , the fuel heater on the 2000 is in the filter canister , leaving the stock pump in place will eliminate the potential starting problem that member ROYAL brought up about as the reason for the factory cutting back pressure on startup .

this is why the guy at carter said to use the 7 psi pump , my concern was the 13 psi pump sucking the line dry between the pumps and he said as long as the volume of the pumps is equal there should be no problem .

the poor design of the banjo bolts and the placement of the pump is causing the failures , an electric pump wants to push the fuel , not suck it thru that much line , the banjo bolt restriction is making the line length problem worse on both sides of the pump .

adding bigger injectors , and fueling boxes is making the problem worse , the stock banjos are barely ok for a stock engine , increase fuel demand and all bets are off .

evan 19-20 psi ??? thats a bit high , did you put a 12v overflow valve in ? if not at that pressure the overflow is open all the time , not a good idea to me . if you can get it to stay at 13 psi , foot to the floor at about the 500 - 550 hp flywheel level then the fuel system is sized perfectly .



[This message has been edited by Mopar-muscle (edited 03-14-2001). ]

 

[HeberRam]

Mopar-muscle... I think you have answered my question, sort of? At WOT, as I understand it the lift pump pressure drops dramatically from say 7-8 psi to 2-3 psi. So if this occurs for a long enough period, this may explain why my injection pump failed because of not enough fuel to lubericate or cool the injection pump!! Some one had made after market braided areo lines which increased the line size before the lift pump on the tank side and also from the lift pump to the injector pump and eliminated the banjo fittings??? Do you know who did this and where can I get them... I think this will solve most of our problems. .

 

[Arcticat]

John, I was under the impression that the overflow valve is open most of the time anyway. Doesn't it need to be open for fuel to get back to the tank? The service manual states that over 70% of the fuel that goes into the injection pump ends up back at the tank, and only a small portion of this goes back via the riffled passage in the head. So... what am I missing here?

 

[J Allan]

Mopar-Muscle,
I added a powermax 3 and Stage lll injectors to my truck not to long ago. What is a way to fix this potential problem before it starts.

Thanks,
Jeff Allan

------------------
Jeff Allan
31D 81199
2000, 3500,4x4, 355 gears Laramie SLT, BD valve Body, BD Torgue Convertor, BD pressureLoc,#14cm wastgate turbo housing, powermax 3 adjustable, stage 3 injectors, custom dual 3" exhaust with dual 4" barrel tubes behind rear tires. Trailmaster SSV shocks, ISSPRO Turbo boost, EGT gauges in piler, K&N air filter, bushwacker fender flares, black nerf bars, hellwig spring helpers, Let the BOMBing begin

 

[csutton7]

Heber ram--brandonF@onemain.com for the upgraded lines-email him

Read the Holley post we are on the verge of getting this thing figured out with the help of Ted J. today.

chris

 

[HeberRam]

Chris... Thanks for the info. . I'll E-mail today... Keep up the good work on the pump issue, I know it can be frustrating, I've been there, done that,,,We all appreciate your work. . Sorry I can't help in this area. . Heber

 

[Brandon]

got to back you up here again csutton, awesome r&d

B... ... ... ... ... ...

 

[Brandon]

well I think we are getting the cart ahead of the horse a little bit

We need to find the best lift pump for our purposes and then build lines specifically for that setup

lets start a thread with people who will be willing to r&d and post about it and then develop a email list or something, well we need to know what kinda pumps we want to put in BEFORE we put in the upgraded lines, because upgraded lines are for stock setup unless other wise specified, soooooooo if you buy or make the lines, and then upgrade the pump, most of the stuff will be junk, I will contribute to this R&D in any way possible, lets get something worked out
blkdemon csutton vuaghn, lets get together on this and go, so we can help all the others out and not waste lotsa money doing it

B

 

[csutton7]

since 1/2 my order is shipped I probably will go with the BG pump and play with both regulators, if I can get them, and get Ted J. 's line upgrade--drill out & adapt what I can & let you guys know what shakes--Ted J. was great today and I will talk to him more tomorrow-yea price is out the door but maybe I'll be able to figure something out that will be beneficial & less costly for us all---now that I may need to drop the tank that tank upgrade is looking good--oh when will it stop--never I hope or until my wife starts squeezing the--well I think you all know what I mean---it would be interesting if Chad & Blackdemon chipped in & left their set ups the way they have it so we would be able to compare the different set ups---well boys what do you say----chris

 

[Brandon]

lets get after it, maybe get nowell to help some too, cant let joe D get ahead

B

 

[Brandon]

lets get after it, maybe get nowell to help some too, cant let joe D get ahead

B

 

[Bart Timothy]

Probably a better way to describe the addition of an extra pump is "series" instead of "tandem".

Ever since these fuel pump issues have cropped up I've wondered why everyone just wanted to replace the stock pump instaed of adding an additional one - even posed the question twice. If these are rotary pumps then in the case of one of them failing, enough fuel should get through to at least keep the engine running (?). Puttiing an extra fuel pump back by the tank is certainly a trick used by hot rodders since day one.

I still think this is a better idea than replacing the stock pump with an after market pump, and by the looks of things, probably much cheaper too.

 

[Mopar-muscle]

put down your VISA and step away from the phone son , its going to be alright #ad


chris , i posted on the other thread , before you order a bunch more parts let me order a carter pump and some lines tomorrow , i have a very good idea on the fix , it will cost about $200 and i will be leaving the stock lift pump in place . i expect to see 10 plus psi with all my HP in tow and my foot ticliking the radiator .

bart i haven't paid much attention to the fuel issue as i have not had any performance decrease , it will be interesting to see if i get an increase .

i was under a friends ram tonite and the stock pump is close to 8 feet from the bottom of the pickup tube in the tank . i know of another member that has the increased size fuel pickup and replaced all the lines to the injection pump , he still ha a fuel pressure problem with an aftermarket HP pump in the stock location , in fact he has burned up 2 of these pumps in the last few months , thursday he is moving the pump back to the tank , we'll see if that fixes the problem , but with his 1/2 inch pickup i can't use his data as gossiple as it will not be support my thoughts fully , i do believe that larger column of fuel being pulled 8 plus feet is what burnt both his pumps out .

jallen , what i listed above is the fix i am going with , whether or not is enough will not be known till the weekend , i need to order parts in the morning , i'll keep the masses posted .

arcticat , i can really give my reasoning for the overflow valve statement other than than my thinking is that its shouldn't be open all the ime , i'll have to read my manual tomorrow .



[This message has been edited by Mopar-muscle (edited 03-14-2001). ]

 

[1tuffram]

What's more important with this fuel issue, the PSI or volume (GPH). Is there a relationship between the two, more PSI = greater flow volume? I would think the amount of fuel getting to the VP44 would be more important than fuel PSI for the pumps longevity.

 

[K_Arts]

Thanks for all of the info that you are sharing with us Mopar.

I've already gone through one lift pump while being stock. I'd hate to go through another one cause of my DD2's and EZ box want more fuel.

Please post the results when you get them... and some pics would be cool too... to show everyone what you actually did.

Kev

[This message has been edited by K_Arts (edited 03-14-2001). ]

 

[BigCarl64]

I shall throw my 2 cents into this discusstion. I have had the Mallory 4140 pump installed for over 6 months now and approx. 15,000 miles. It has worked liked a charm. I also have the upgraded aeroquip lines and 90 degree fittings installed at the same time, as well as a fuel pressure gauge. I also have DD stage 3 injectors along with the new TST PowerMax 3 box.
The pump is mounted on the frame rail and wired into the stock wiring harness using weatherpack connectors. When the key is turned on, w/o cranking engine, the pump will run for approx. 2 seconds, then shut off. Bumping the starter w/o cranking the engine, the pump runs for about 30 seconds.

Results: Pressure steady at 13 psi with no fluctuations with the pump running. With engine running at idle, still 13 psi. Normal cruise at 70 mph, 12 psi. WOT run from dead stop with PM3 off, psi drops to 11, then quickly returns to 12 psi. WOT run with PM3 on at setting 6, psi will drop to 8, then recover quickly after easing out of the throttle due to excessive speed...

All in all, I am very pleased with the Mallory pump. It has no problems keeping up with the demand for fuel.


[This message has been edited by BigCarl64 (edited 03-14-2001). ]