? Cummins C-series lift pump ?

[Pit Bull]

I think if you want to fix the problem you want bigger line size and lower PSI. I think that the PSI spikes are killing the pumps, and the objective is fuel flow not fuel pressure. "0" PSI is fine as long as the FP is getting all of the fuel it needs. I think you guys are trying to fix this problem with a bigger hammer, when what you need is a better nail

 

[BIG BOB]

redneckdr,



When I am referring to lower volume, I'm referring to 50 to 100 GPH at 12 to 18 PSI. I am also seriously thing about installing a regulator to enable the pump to flow as much as it wants without restrictions.

I am also going to change the Racor filter between the tank and pump. Not sure if I will just remove it or increase the flow to match the pump. It only flows 45 GPH, I can change the spin-on filter. I have the option of filter, 45, 60, 90 and 120 GPH and anywhere from 2 to 30 microns. The bad thing about going to the higher flow is the height of the filter increases, causing it to hang below the frame rail. I might try another type of filter.

 

[TowPro]

I also called Aermotive today, they said this pump "has not been tested with diesel, but if something goes wrong with the pump, we will fix/replace it, unless it was caused by the diesel"



They also said he knows of many being used in diesel applications, he said the life expectency is about 1000 hours (which he said is about 30K miles) but I think that number was for an application where there is a feed point from the bottom of the tank (not sucking out of the top) and with gas.



This pump has a built in regulator, where it will redirect the over 20psi back to the inlet.



YOu should see 18-20 psi if you plug the end, the 150gph is when there is no pressure, but at 10psi it will still be pumping around 120psi.



ONe thing he did ask that I did not know the answer is "how much fuel flow (gph) does our system use?" I have seen figures for how much we can burn per hour, but has anybody ever tested a stock liftpump to see what GPH it is doing while holding something like 10-15psi?

Originally posted by BIG BOB

TowPro,





I also called Aeromotive today, they recommended their "Street Rod Pump #11203". However, they said their was no warranty with diesel.



Anyone got any ideas?

 

[Mopar-muscle]

a stock unmodified 2000 up filter and housing flows roughly 45gph , moded maybe 60 gph .



somene needs to crawl under a few big rigs to see their setup?



maybe a transferflow in the bed with a pickup point in the bottom is best , ditch completely the the stock tank ...

 

[RustyJC]

Thinking Outside the Box!

OK, how's this for thinking outside the box?



As a rule, large industrial (stationary) diesel engine installations are designed to conform to Diesel Engine Manufacturers Association (DEMA) standards. DEMA specifies that you will have a transfer pump to move fuel from the outside storage tank to the "day tank". The day tank is a small fuel tank normally located in the rafters of a power plant building which then gravity feeds the diesel fuel system on the engine - a flooded suction design. Fuel level in the day tank is controlled by either a float-type system that returns excess fuel to the storage tank (reduces transfer pump cycling) or a level controller that turns the transfer pump on and off to maintain day tank level.



What if one were to rig a small tank in the engine compartment that is fed by a pusher pump back near the main fuel tank. The outlet of this small "day tank" would then be piped to the inlet of the stock lift pump. This way, the lift pump has a much easier life - it doesn't have to draw fuel all the way from the fuel tank in the rear of the truck, and it will operate at a slight positive pressure at its inlet (assuming the tank is mounted higher than the pump inlet. ) At the same time, the transfer (pusher) pump is only having to push the fuel against gravity since the day tank is not pressurized, so it should last longer as well.



Hey, just a thought... ... .



Rusty

 

[Joseph Donnelly]

The 12 valve camshaft with the fuel pump lobe can be used in the 24 valve engine, if the correct cam lobe profiles are ground onto it for the 24 valve head. Doesn't cost $4000 either.

 

[TxDieselKid]

Originally posted by Joseph Donnelly

The 12 valve camshaft with the fuel pump lobe can be used in the 24 valve engine, if the correct cam lobe profiles are ground onto it for the 24 valve head. Doesn't cost $4000 either.

Joe,

You're right, the DD cam does not cost around $4,000, but from what I heard(might not be true) Sheilds had a kit to do it for this much wich included the pump.



Sorry for the confusion,

Andrew

 

[Steve St.Laurent]

Scheids kit at ~$4500 used an electric lift pump, not the mechanical pump that 12v trucks used. It replaces the VP44 with a P7100 - not sure what it included as far as changing the dash over though, didn't get that far - I saw $4500 and that ruled it out as an option for me right away!

 

[TxDieselKid]

Originally posted by Steve St. Laurent

It replaces the VP44 with a P7100 - not sure what it included as far as changing the dash over though, didn't get that far - I saw $4500 and that ruled it out as an option for me right away!

That is what i was talking about, it uses the P7100 insted of the VP, so the cam has to get a lobe in it for the mech. lift pump that the P7100 needs to drive the pump.



Am i making any since cause it makes since to me,

Andrew

 

[Steve St.Laurent]

You didn't read what I said correctly. The Scheid conversion puts a mechanical P7100 pump on the engine that replaces the VP44 BUT it still uses an electric lift pump - not the stock 24v one, a higher pressure electric pump. Therefore they DO NOT change out the cam for one with a lobe to drive the mechanical lift pump. This also wasn't mentioned above but you couldn't use the 12v mechanical lift pump with the 24v VP44 - the pressure would be too high. The point of the Scheid conversion is to completely get rid of the VP44 and have a long life P7100 pump.



-Steve

 

[stephen bolger]

Steve where can i find more information on. The Scheid conversion puts a mechanical P7100 pump. I am looking at a used truck with a 12 valae that is dead and i have a 2000 24 valve from a wrecked truck that i would like to put in with the p7100 pump.

 

[RBallard]

Shooter or anyone else for that matter,



Can the lift pumps be taken apart the shaft coupler replaced. I am curious to what the coupler looks like, do you have any pictures?



Thanks,



Bob Ballard

-- email address removed --

Stephens City, VA

 

[Royk]

Forgive me, for I don't know a whole lot about fuel pumps. What is the possibility of using the DC in-tank pump used for the gassers? I just traded a gasser 2500 for my CTD and, while I never studied the old tank closely, it looks like the same tank. Big round opening on top of my current tank looks like the same opening on my old truck. The fuel pump in my old truck lasted about 110,000 miles. I believe it puts out 30-40 psi.



-Roy

 

[RBallard]

I am not an expert and I did the same as you, trading in a gasser 2500 for the CTD last July, the problems I see with the gas fuel pump is that you would need a pressure regulator, I have heard the Injection pump doesn't like high pressure nor low but I think most importantaly, diesel fuel is a more dense fluid and is harder to push/suck and would where the little guy out.

 

[redneckdr]

Borg-Warner pumps

well, another of my lame-brained ideas may be shot to heck... finally got prices on the BWD pumps today. EP4600P (7 PSI) is $113, and the EP4601P (15 PSI) is $131. the store i priced them at was dumbfounded that i thought they had a lifetime warranty. i'm not sure i trust his info, however, since the catalog says "limited lifetime warranty' quite plainly.....

 

[JTBMC]

Steve

Im not sure if the coupler can be sucessfully replaced or not.

I used a dremel tool to open up 2 pumps and distroyed the motor housing in the process. The other I pryed open with a screw driver and hammer in the vise. The last one was given a repreve.

I do plan on sending Ray T a pump to look at. If some one knows how to open one up with out ruining the housing let me know. I dont have any pictures or a way to take them. I'm still in Neanderthal mode

I borrowed the idea of gettig inside the pump from Shooters post . Just got my curiosity up and had to do it.

TJ

 

[TxDieselKid]

Steve,

Didn't know that much, thanks for the info. All I really knew was that it replaced the VP44 with the P7100. Wasn't reall sure about what all went in to it so I assumed it needed the extra lobe in the cam.



Still learning about a CTD, just not from my school books,

Andrew

 

[w-cummins]

Originally posted by Steve St. Laurent

You didn't read what I said correctly. The Scheid conversion puts a mechanical P7100 pump on the engine that replaces the VP44 BUT it still uses an electric lift pump - not the stock 24v one, a higher pressure electric pump. Therefore they DO NOT change out the cam for one with a lobe to drive the mechanical lift pump. This also wasn't mentioned above but you couldn't use the 12v mechanical lift pump with the 24v VP44 - the pressure would be too high. The point of the Scheid conversion is to completely get rid of the VP44 and have a long life P7100 pump.



-Steve

So. . I see, we get rid of the "bad VP44" and replace it with the "long life" p7100. Then we put the really "GOOD" part of a ISB back on the truck, another electric lift pump..... and we are right back where we started as far as a long life goes! BTW other than the "little" cam problem, why not run the mechanical pump with a bypass regulator?



William Cummins

 

[1tuffram]

Originally posted by tjlaffite

Steve

Im not sure if the coupler can be sucessfully replaced or not.

I used a dremel tool to open up 2 pumps and distroyed the motor housing in the process. The other I pryed open with a screw driver and hammer in the vise. The last one was given a repreve.

I do plan on sending Ray T a pump to look at. If some one knows how to open one up with out ruining the housing let me know. I dont have any pictures or a way to take them. I'm still in Neanderthal mode

I borrowed the idea of gettig inside the pump from Shooters post . Just got my curiosity up and had to do it.

TJ

Keep us updated on Ray's analysis and if it's possible to "BOMB" the lift pump. Is the motor housing press fitted onto the rest of the pump? Maybe a removable housing can also be fabed up. Heck might as well just start from the ground up and build a "TDR exclusive" lift pump , maybe we could incorporate some of the "good" parts from the failed OEM pumps (elec motor, etc) to help keep costs down.

 

[1tuffram]

TTT