Lift Pump replacement. How hard?

[mikepvg]

Prostock

Do not go by "25psi per rated rpm". NOT detailed unuff.

Fuel filter-Outlet side should read 18-24psi @idle & 28-36psi @2000rpm noload.

If u do not get these figures u must go thru the entire fuel system step by step w/ the little things 1st. Very easy. The lift pump replacement will be last.

1st will be pre-screen fuel filter check: https://www.turbodieselregister.com/ubb//Forum1/HTML/003406.html

Next will be checking psi w/ TST fuel adapter available @ http://www.tstproducts.com/gauge_kits.html

I started out w/ only 10psi https://www.turbodieselregister.com/ubb//Forum1/HTML/003600.html

Then I got up to 22psi at rated rpm. Is this OK? No https://www.turbodieselregister.com/ubb//Forum1/HTML/003929.html

If u want to rev to higher rpm, simply adj High Idle screw (but this won't help until everything else is in order): https://www.turbodieselregister.com/ubb//Forum1/HTML/003380.html

Good luck
Mike
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94 2500HD 4X4 5sp w/GearVendors O. D. 4:10 L. S. D. , K&N Oval w/ Pre-Filter, Straight Exhaust, Geno's Fumotovalve, AW-Direct Idle Controller, DiPricol Boost/Pyro/Fuel w/ Kevlar BSS line, Mag-Hytec Rear, 126K miles. Halon Protected, NRA Member. V1=Anti-"pinch" protection. KDP 125,700-NM-WT Insurance

 

[FParisi]

Tom Sorry, you said your first Cummins- I thought you may have come over from the dark side!
Mike Thanks for the links! I plan on checking + cleaning mine next week.
Frank

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95 Blue 2500 4x4,3. 54,33x12. 5x16. 5 tires,catless,BD transmission cooler,Pacbrake; gauges-transmission temp,boost, pyro;K&N; higher power cam plate ?Bosch?slid forward;afc adjusted some
96 Alfa SeeYa 30RK w/2 sldes- 12,000lb

 

[Jeff Knight]

Hi Tom,
Ihave 185000 miles on my origional lift pump. It's not as common on the 12v. If you want a second opinion I recommend you call Diesel Injection of Pittsburgh. They are very good with cummins. Good luck. Jeff

 

[DieselB59]

Looking at your shop's diagnosis, I notice a problem with his findings. If the spring in the valve is weak, then the valve will open at a lower pressure, thus keeping the fuel pressure inside the pump at a lower pressure as a result. I am a Bosch diesel injection specialist and I use a gauge with a fitting in place of the banjo at the pump also. If I were you, I'd buy a new valve from the dealer and replace it and see if you notice a difference. We don't replace a whole lot of the 94 and up lift pumps unless they're puking fuel out of them. You can also tinker with the spring inside the pump by giving it a stretch just a hair and it should be back to operating specs. Just pull the valve out and hold it with a 19mm wrench while you loosen the 14mm bolt out of it and remove the spring while being careful that it doesn't shoot out as you pull the bolt out. Stretch and reinstall. Remember how it was when it came apart. It'll make reinstalling it much easier.

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Chris Timochko
*Association of Diesel Specialists Certified*
AUTO WURKS DIESEL R&D TEAM
1997 5sp 4X4, Rhino Linings, Espar Heater, A. W. D. HX40 turbo, ATS 3pc Manifold, BD 4" Brake, Marine Compression, A. W. D. Custom Tuned Injection Pump, A. W. D. Intercooler, A. W. D. /Mallory Fuel System and Braided Stainless Lines, A. W. D. 370B Injection Nozzles, Delivery Valves, Governor & AFC Spring Kit, Psychotty Air, NOS Diesel Kit, A. W. D. 6" Chrome Exhaust System, BD No Smoke Valet Switch, McLeod Dual Disc Clutch, Mag-Hytec Rear Cover, Cummins Chrome Kit, Optima Red Tops, Hadley Bully Horns, Hurst Line Loc, Goodyear Wrangler AT/S 305/70/16s. 15. 50@97mph on Goodyear All-Terrain tires. Dynoed at Ida's: 435 hp at the rear wheels.
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Project U96 - 1996 3500 2WD racer. A. W. D. Marine Ultra Low Compression, A. W. D. Teflon-coated Pistons, A. W. D. High Lift Camshaft, Ported and Honed Cylinder Head, Intake and Exhaust manifold; A. W. D. HX40 Turbocharger, ATS 3pc Exhaust Manifold, A. W. D. Water Mist Injection, A. W. D. Custom Fabricated Fuel System, Race Spec A. W. D. /BD P7100 Injection Pump, A. W. D. Custom High Flow Fuel Injection Nozzles, BD Auto transmission and Custom TC, Weld Draglites, Goodyear Eagle Drag Slicks, 5" Single Stack Through The Bed, Mag-Hytec on Rear and Transmission. 11. 54@115mph

 

[FParisi]

I think you might want to get back to basics.
You don't say if this is your first diesel- mine has been an education, and this forum is the place to get it. The Cummins is governed to cut back on fueling at about 2200rpm and develop peak torque at 16-1700rpm could that be what you felt? Also check the air filter- once I got the K&N my filter minder hasn't moved. Good luck + let us know what you find out.
Frank

 

[Dkevdog]

I've got to have mine replaced on my 96'. **** mechanic charged me a sh*tload of money to get in there and work on it. Told me all that pukin fuel was a result of a loose fuel line. I told him to replace the pump, he said he fixed the fuel line. Guess what. STILL PUKIN FUEL!! I told him my good friends at the TDR could diagnose the problem on line better than he could under the hood. Now I'm looking for another mechanic. I'd like to work on these things myself, but at this time my knowledge is limited #ad
. I'm sure before long though I'll be screwin... ... er I mean fixing my own truck.....

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Kev

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1996 Ram 2500 4x2, Auto, Banks Power Pak, FABTEC 2" lift, Rancho RS9000, 265x75x16 on custom wheels, Line-X, Toolbox, Westin Steps, Lund Stainless... ..... More to come

 

[Joe G.]

Most stockers will do 2700 to 2800 before defueling occurs with the P7100 pump. Mine would do 2800 before I started messing with it. Now it will defuel at about 3000 which is the red line. One problem is when the stocker gets too far above the sweet spot it is kind of a dog. Mine has a #5 TST plate in it now and goes like it is fleeing from the law until the governor kicks in.

 

[Cooker]

Prostock,
I'd check the prefilter first, although I don't imagine it is the problem it is a free (or $7 if you buy a new screen) easy task. I'd really replace the overflow valve. Cost is $45 from Piers and it is an easy, first repair on you new Cummins.

-Ryan

 

[Prostock]

How do I get in contact with Piers if I want to get a new overflow valve?

 

[HEMI®Dart]

Prostock,



I would check the overflow valve first. If you have a pressure gauge, try pinching the rubber fuel return line shut and see if you get better pressure. If your lift pump is still the OE one, they have been revised about 3 times. It very well could be your pump.



I have a good '94 overflow valve that I changed out. My pressure was no different with the new one. I could send you the old one to try.

 

[Prostock]

Thanks for the offer. They are going to try the valve first, and if the pressure doesn't come back up go with the lift pump.



Hopefully the truck will be done today.

 

[Prostock]

They changed the overflow valve, and the pressure did not change, it is still low.



They're taking the new valve back out, and changing the lift pump.



Also said it might have algae in the fuel.

 

[Cooker]

Algae in the fuel? Wouldn't this be an issue of clogging the fuel filter? A new filter would register higher pressure even if it was only for a few seconds until it colgged again, right?



Sorry to hear it wasn't as easy as the overflow valve. At least they tried the less expensive part first before throwing the more expensive one at you.



-Ryan

 

[Andy Perreault]

Originally posted by RHARVEY

I had the lift pump replaced on my 12v 3 weeks ago. I was loosing prime when it was parked up hill over night,level or down hill it was ok.

I called Cummins in Indiana, and the first thing out of his mouth when I described the problem was that a seal in the lift pump was going bad.

Don't forget about the notorious "cheap rubber fuel line" on the 12-valves. It will cause loss of prime, too. Do a search, I know it has been discussed before. I wonder how many times a sleazy mechanic has told an owner with a leaking fuel line that he needs a new lift pump?

(Rick, I'm not implying that may have been your situation, but your post reminded me of the symptoms of bad fuel lines that others have experienced. I thought I'd mention it for the benefit of Prostock Tom and other new owners. )

Prostock, just a suggestion, if you do have to replace the lift pump, replace the short fuel line that feeds it at the same time. They've been known to disintegrate.

Andy

 

[Prostock]

They said the pressure dropped under load.



The fuel filter contamination problem is minimal. They did install a new fuel filter and it made no change in the pressure.

 

[Prostock]

I picked the truck up tonigh, and it seems better.



The true test will be when I have a chance to hook up my car and trailer and take it for a spin, which won't be for a couple of weeks.

 

[Blakers]

Well I got to meet Tom's (Prostock's) truck , but not Tom at Diesel Injection of Pittsburgh . I was sick as a dog anyway, so it's just as well for Tom. Anyway, they did a good job diagnosing my truck.



Blake

 

[LI Camper]

Looks like mine is dying right now. Leaking fuel from plunger. Cummins parts says no kits just replace pump. Looks like I got another job. Just finished dowel tab and found leaking pump. Just can't win. Wife won't like this.

 

[plater]

LT CAMPER



This happen to me about a year ago I took my pump apart cleaned it put it back in no more leaking . It may or may not work for you. The rubber boot just pops off then thiers a plastic nut that holds the plunger in. It did leak once after that about month ago I just pump it a few times it quit again. I'll probaly change it before I take it on a long trip since they are only around $150. 00. The truck ran just as good leaking or not .

 

[LI Camper]

Platter,

Yeah mines not leaking now but I leave for Florida on friday and I don't want to get stuck. The pump and gasket cost me $144 at my Cummins dealer. I didn't ask about warranty as I've got a #8 TST plate installed. I hope to do the work on Monday. Don't know if I'll drop the filter and work from the top or drop starter and work from bottom. I changed the fuel lines recently and I seem to remember that there was a lot of access from top but the diff is in the way on the bottom even with the starter removed. We shall see.