Lift pump pressures?????

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Allright gentlemen, somebody help me out here. I need to know what the psi is suppose to be on the lift pump for the 99 24v.

Cranking?????

At idle?????

Running down the road????

WOT?????

Any help is greatly appreciated... JW

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John W. - Indiana - Black 99 4x4 QC Sport LB 24V AT 4. 10 Gears Loaded Including Leather and cab lights,285 BFG A/Ts , 16x8 American Racing Baja Wheels,Bed cover, Bushwacker flares, Ventvisors, Rancho RS5000 Steering Stabilizer, Cobra 148GTL CB mounted on a custom cb bracket by "JOHN", Walker #21468 straight thru muffler... and my Halo light still works!! Bomb My truck?? No way!!(Wink Wink) More to come ... And the RS9000's are in the UPS truck as I type!!!!!!!

[This message has been edited by Truckman (edited 06-24-2000). ]

 

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The generally accepted figure is no less then 10 psi at idle. I don't care what the idle pressure is, what is the pressure at WOT. I installed a digital fuel pressure gauge today and on the test drive I noticed a drop from 11 psi to 4 psi. This is with upgraded 3/8's lines and Aeroquip fittings. You stockers are gagging for fuel. I will install my Holley lift pump next to see if I can effect an improvement. Beyond that I may go for the fuel preporater.

 

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I have 10-10. 5 at idle, 7 +/-1 going down a flat interstate with no load. I have stock lines and etc.

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2000 2500 Red Sport quad cab, 4x4, K&N, DDI's, straight piped, boost, pyro and fuel pressure gages, boost module, mean looking set of 33. 5" tires, Snap On diamond tool box, Marine Corps window sticker, Semper Fi!

1972 340 Cuda'. Original tripple black 340 car w/air! Good clean car, super stock springs, Weld Prostars, strong 340 with a 727/4000 stahl, 4. 56... . Bombs away!

 

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I have 20-Key on,10-high idle,14-idle.

Steve

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Y2K 3500 SLT+,4x2,Black/Camel,leather,LSD,Auto,3. 55,towing,rhino-liner,eagle series 58 alum wheels,JRE 4" exhaust,VA CPC

 

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<font color=red> Am at 13 at idle,12 while cruisin 70... 10poundds of boost, and 9 while am Floored ... before i put the fuel lines in... Floored used to be 6

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99 Quad,Long bed,4x4, SLT,Auto,K&N,Mobil Super Delvac 1300,fuel line up-grade from lift pump to filter and from filter to injection pump, Suncoast coverter,BD valve body and pressure-loc,Mag-Hytec trans pan,Amsoil ATF-4,Auto meter Ultra lite gauges:Boost,EGT,Fuel Pressure,Trans Temp, "true" Jet-Hot Coated 5 inch exhaust from turbo to tail pipe(over the axle)Borla shoot-out muffler,DD stage 3 injectors and boost module,HX-40 16cm,here and waiting to fab-up a a new adaptor,Next Jet-hot the exhaust manifold and turbo housing,..... finally a blue box or TST box or?????

 

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I measured mine after the fuel filter and got 15- key on, 12- idle, 8-9 reving through the gears empty and it droped all the way down to 3-4 at WOT in fifth up a big hill at 2800 RPMs .

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2001 black dually,4x4, 6 speed H. O. ,loaded up. Jacobs E brake, lighted running boards, toolbox, solor visor, mag hytec cover, rhino lined, diamond tread rail protectors, mud flaps with genos chrome plates, megs exhaust tip, VDO vision series pillar mounted pyro & boost gauges, rerouted blowby bottle, torklift class 5 double tube hitch. Rippin' through the gears with a smile on my face... no more auto for me!

 

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I don't see why we should have a greater then 50% depriciation in fuel pressure. Can you imagine a transmission which had a better then 50% parasitic loss? What about a water system with a better then 50% drop in pressure while being used? Seems to me that any system which drops off by 50% while under load is miss engineered.

 

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Mine checked in at 17psi at idle and 11 at 2750 rpm. All lines and lift pump are stock, but my banjo fittings are the new styke with the 4 holes.

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99 2500 QC 4X4 5sp / made in Mexico /
3. 54LSD 285 75X16 AR Atlas / Hadley airhorns / DDIII - 4in exhaust, turbo back - HD clutch / ISSPRO guages / 33' Hitchhiker triple slide

 

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While you are on the subject, I have a question. How does the pump overflow valve effect this? Could you modify it to open at a higher pressure? If so, then wouldn't your pressure go up? However, would you overheat the pump? I might be over my head with this question, but I am trying to learn. Thanks.

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99'2500 SLT QC LB 4x4
white/agate, 5spd, trailer, camper, 3. 55LSD, 241HD, cab lights, 3500 tailgate lights, mopar mud flaps, luverne SS nerfs, diamond plate rails, Weatherguard box, Banks 4inch, Isspro Boost/EGT gauges(pre), 265 BFG KO's, ... more to come

 

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On my basically stock ETH:

Key on--14psi
Idle 11-12
Cruise 8-10
WOT 6

No fuel line mods yet, but soon!

Vaughn

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2001 Ram 2500 QC SWB 2wd, Patriot Blue/Driftwood, HO Cummins & 6-speed, 3. 54LSD, Cab & Fog lamps, Camper & Tow Pkg.
BOMBings: K&N RE0880, straight piped, debadged body, AutoMeter Sport Comp Boost & Pyro gauges, Amber turn signals
Performance: 245rwHP on BD Dyno, 0-60@ 11. 5 sec 17/22 mpg city/hiway
8990 miles (6/26/00)

 

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I talked to Lawrence at DD about this lift pump problem. He is doing some R&R to come up with some hard facts and possible cure.

There are actually two supply pumps for the main pump. He showed me a torn down injector pump and the gear pump that's built into it to help supply the main injector pump. It stands to reason if the lift pump is putting out so much pressure and the gear pump is sucking it up (remember the more revs the more the gear pump will suck) the difference we are reading on our gauges WOT may not be as important as we think. We could still have plenty of flow without much of a pressure reading between pumps. I wonder if there is a way to monitor the fuel being returned to the tank.
Has anyone actually lost an injector pump? Can anyone say their engine is hesitating due to a lack of fuel? I sure wish we had some answers. .
Ron


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'99 Quad long bed, 4x4, 5 speed, 3. 55 limslip, DD stage IIs/boost module and elbow, US Gear D-brake, 4" exhaust, gauges, stock filter, air bags and a bunch of other stuff

 

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Measured at the outlet port:

Idle: 10. 5
Wide open throttle in neutral: 8. 5

This is with a new filter just installed.

What differences are you guys showing between the inlet port and the outlet port?

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99 3500 QC 4X4 5sp 3. 54 K&N air filter, DiPricol gauges, 275 hp injectors, Pacbrake, Westin nerfs, GN hitch, Tekonsha Brake controller, Mopar seat covers, Husky mats, silencer ring removed, Draw-tite front receiver

 

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Ron, yes a number of people have lost injection pumps. Scott1 went through 2 or 3 I think on his last truck before any bombing started. I just installed a fuel pressure gauge on my truck last week ( https://www.turbodieselregister.com/ubb//Forum3/HTML/001088.html ) and found that my lift pump pressures were way low. They were at 7-8 psi at startup and idle (idle after driving is down around 4 psi) and under ANY acceleration it went instantly to 0!! I'm not talking WOT here just slow acceleration it would go to 0. Once I would get up to speed (at 55 or so) it was at 0 and I'd push in the clutch and let it idle for a couple of seconds and it comes back up to 4 psi and then I'd let the clutch out and it would stay there until I accelerated (even 1 mph, or uphill). At speeds above 60 it wouldn't go over 0 no matter what I did. I replaced my lift pump yesterday (with a stock pump) and now have 10 psi startup and idle (and comes right back to 10 at idle after driving. Cruise it's at 6 psi. Partial throttle acceleration is also at 6, full throttle acceleration with the powermax off it will drop to 4, and full throttle with the powermax on it will drop to 1 (takes 9-10 seconds to get that low though). Ninearrow - I haven't put the switch on my gauge as of yet so I'm just monitoring the pressure before the filter right now. The wire's all run into the cab and all - I just have to install the switch. I'll post the difference between the two once I get it installed (probably this weekend).


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-Steve St. Laurent - President of the Great Lakes TDR, Chapter Forums Moderator
'98 Quad Cab Long Bed (CMNSPWR), 4x4, ISB, 5sp, 4. 10 LSD, Prime-loc remote fuel filter, boost & pyro gauges, TST Powermax, muffler eliminator, 5" chrome tip, BD Exhaust Brake, Isspro turbo temp monitor, Permatech spray in liner, Grizzly stainless nerf bars, Stull SS grill & bumper inserts, Front Draw-Tite receiver, BFG 285/75R16 AT KO's

 

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Steve,
Thanks a bunch for this post!
So you went out and bought a new one, probably what I should do so I can relax when pulling the fifth wheel. How much was that sucker? Did you ever have any indication it was bad before metering? Sometimes I feel a lurch under heavy pulling and it scares the beejesus outa me. I ran a very bad gauge on mine and it seemed to zero out very easy.
At May Madness a BD guy told me they just stick another electric pump in line. He said if I called them he would tell me what brand and model pump they used, even though they didn't sell it.
I am hopeing HVAC's sales will go to hell #ad
so he can get his R&R butt installing the pump he has plans for!
Thanks again for any info...
Ron

 

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I paid $130 for the lift pump direct from Cummins plus $1. 60 each for 4 gaskets/washers for the banjo fittings. I didn't have any indication before adding the gauge at all - that was the scary part for me!! #ad
Looking back on it now there was one indication a LONG time ago. When I had Cummins Michigan install my prime-loc (28,000 miles ago) it took the mechanic over an hour to get my truck re-primed and running again. I now know that is indicative of a bad lift pump - so I've been driving on a bad one for 28,000 miles with a TST Powermax no less! Unforetunately once you have a prime-loc the opportunity to discover it in that manner is gone as the prime-loc has check valves in it so you don't lose the prime! I'm sleeping much better now with my new lift pump and having the gauge to be able to monitor it.

-Steve

 

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Guess I'll be going out to Cummins. I thought the pumps were over $400. I would also like some piece of mind. It doesn't look like it's hard to replace. Maybe the old one could be rebuilt for a spare?
Thanks again Steve,
Ron

 

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Hey Ron & Steve, I installed my new Holley pump yesterday and it is far outperforming the stock pump. Now I need to determine if my old pump was typical of the majority of the oem lift pumps or if it was in need of replacement at only 47,000 miles.

 

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How loud is it HVAC? All the holley pumps I've ever used on our off-road trucks are extremely loud. What kind of pressures are you seeing with it?

-Steve

 

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<font color=blue>Steve -

Part of email Mr HVAC sent me last night.....

I could tell a difference as soon as the truck started, rock steady 11 psi. While
driving it is much more stable at 11 and it drops to 9 under flat out accel. I will try it again with the box on to see what the full load race scenario does. I can tolerate 9 under load or even 7.

Hope this answers part of your questions..... I am looking into that Holley Pump as well once I milk HVAC for some more information on it.

[This message has been edited by KatDiesel (edited 06-30-2000). ]

 

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<font color=red>HVAC... hate to rain on the parade... but can the pump you are using take the abuse of continual use?... I dont think the holley will even come close to 47k... hey i might be wrong... and yes holleys are as loud as Kim Cattrell in the original Porkys movie... jus my 2 cents... JB

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99 Quad,Long bed,4x4, SLT,Auto,K&N,Mobil Super Delvac 1300,fuel line up-grade from lift pump to filter and from filter to injection pump, Suncoast coverter,BD valve body and pressure-loc,Mag-Hytec trans pan,Amsoil ATF-4,Auto meter Ultra lite gauges:Boost,EGT,Fuel Pressure,Trans Temp, "true" Jet-Hot Coated 5 inch exhaust from turbo to tail pipe(over the axle)Borla shoot-out muffler,DD stage 3 injectors and boost module,HX-40 16cm,here and waiting to be installed, Next Jet-hot my ATS exhaust manifold and turbo housing, and special thanx to rob for swaying me on a 4 wire Blue Box(incoming)