Engine/Transmission (1998.5 - 2002) Operation Lift Pump Longevity (long)

[15w40]

And here is a picture of the circuit. It measures about 3" x 2".

 

[rweis]

15-40,



I have the solid state KV type pressure senders and gauges from Westach at all my pressure senders. They are truly unique. I thought the same, if it is approved for aircraft use then surely it will stand up in diesel applications.



I use 2@30psi KV type senders for FP and had Westach do a dual 30/30 psi gauge. I measure pre and post filter (see sig for the tank to VP line discription). I use Bill Flemings idea of the needle valve only slightly opened, I then connect a 24" SS braid line for buffering and ease of mechanical mounting the actual pressure sender for stability away from the vibrations of the engine.



I would be glad to test one of your PWM units. My LP is down on the inside frame by the tank.



I am totally intrigued with the idea of PWM of the LP. I was wondering if 10Hz might be a little low.



There is still going to be LP failure, but this should lengthen the MTBF significantly!



Bob Weis

 

[Ncostello]

All I can say 15W40 is simply... outstanding!! A real out of the box solution in the works!!



In the case of a Carter pump, the internal overflow (bypass) valve wont be opening and closing constantly thus weakening the spring... ending in failure. If the Carter internal bypass is set to open at 15psi... and a system is always at 15psi more or less... the valve would go through alot of cycles in its life. Just a thought out loud.



I checked with the FAA and the Carter pump is specifically not approved for use in aircraft... hehe!! Glad to see you using top grade components.



EDIT: 15W40... I forgot you already mentioned the spillback valve issue in your second post. Sometimes its good for me to go back and re-read the posts so as to not forget whats already been written.

 

[15w40]

Thanks for the encouraging words guys. I just put a lot more info in the reader’s rig section. Click on “Lift pump idea” to pull up the pictures.



rweis, I don’t plan on going into business selling this controller so I am offering all the info for someone to make their own or market to others. I have learned so much about the Cummins from reading the posts over the years that this is a donation to the info pool.

 

[rweis]

15W40,



Nope, wasn't offering to do a business, just that I already have a pre and post KV 30's with Westach dual gauge already in a system that is functional with a OEM LP without anything else that would introduce variables. I also have stock engine and tow a 8k RV that I can run WOT for long periods of time to see how that part of the equation works. Thought it might provide a useful test bed.



When you are comfortable with the circuit and release it, I am going to build one anyway because you are thinking outside of the box.



I have a question though.



I looked at a PE4100 because I feel it is well built but outside of my parameters of where I want the VP44 to deal with. I feel it has too high a psi for my liking, but is externally bypassed, which should help in the spring check ball bypass department. If I understand your PWM I can dial in the psi (ie the pulse) I want so the actual characteristics of the pump used now become of MUCH lesser importance, and actually of almost NO importance as long as it can supply the volume at the "selected" psi. Am I reading that correctly? That would open up a whole range of possibilities to the "bomb" folks



Of course, everyone has a favorite LP they will try it on and the results from multipoint testing should yield interesting data.



Sorry if I conveyed a business deal approach, that was NOT the intent. I offered because I have a Westach KV system and a really good OEM LP that could be a test bed that the inventer (you) had not input your ideas onto.



Bob Weis

 

[Ncostello]

15W40... I see you've installed some socketless type push on fittings on the PE pump. I think thats a good call. They seem to work well and look good.



I have almost decided on my hose type and fittings. I went to the shop at work today and found the aeroquip equivalent hose and fittings made by Gates. Its called LOL Plus. Its a 300psi hydraulic hose that is intended for diesel and oil. It also uses the same push on fittings. In fact it cross references with aeroquip 2556 which is their nitrile liner/weave/nitrile cover hose. Its avail in about 8 colors. We have about 100' at work plus a bin of all the fittings. Didn't realize this but I'm glad I found it cause it will save me a fortune. I kinda wanted to "buy" everything so I would have a cost account for someone else trying something like this so I will have to artificially add the cost in. I figured buying aeroquip stuff would cost me around $200-$250... so I'll take the savings when I can. The Stanadyne stuff already cost me $282.



I assembled a connection (simply push hose on fitting) and clamped the fitting in a vice. Me and another guy pulled on the hose as hard as we physically could and it would not come apart. Then it still held 150 psi air pressure. So its good. The only thing I wish it had was the fabric weave outer sheath cover as the Gates LOC hose does. LOC hose is the same hose but has the cover. We didn't have any. But the Nitrile cover is tough enough and I jabbed it with a screw driver several times and it wouldn't puncture. Real scientific here!! I am posting some photos of the 3/8" hose and fittings in my Stanadyne FM100 photo album.



15W40... I'm not a logic expert in electronics but I have a question. In the event the pressure sender fails, what default mode does your controller take. Does it go back to normal 15psi constant... or does it shut down or?? I didnt study the diagram too close. Just thought I'd ask. I assume it sees a pressure drop and tries to compensate continuously by increasing to the max setting.



Gates LOL diesel hose photos

 

[15w40]

rweis, the KV30s should work with this circuit. Even with ½ the output voltage of the KV15, it should be possible to just turn the pot to get whatever pressure you want. The PE4100 and the PE4200 are almost identical in construction. The pump and motor are the same. The difference is the spring used in the spillover valve, with the 4100 being a little weaker.



Ncostello, I thought about what would happen if the circuit fails or the sender fails, and decided a roadside fix would be simple. If the sender fails I would just unplug it. This will cause the control circuit the go to 100% duty cycle. If the circuit fails, re-attaching the “+” lift pump wire to a 12 volt source will run the pump at full speed also. If the pump fails … well I guess the quest for a pump continues.



Those hoses look a lot like the aeroquip. I wish I could have found an inexpensive source.

 

[Ncostello]

Well... I called Gates Corp. and an engineer told me not to use LOC or LOL Plus push on hose for any fuel application. We've used it here at work with no problems on diesel applications.



The gentleman said to use RLA or their industrial hose with crimp on fittings. . I asked him why they specifically say "use with diesel" on their website page for LOL... and he said "well we dont recommend push on hose for any FUEL applications". I asked why and he said quickly that the nitrile blends in push on hose wasn't good with diesel. ???



Aeroquip's nitrile hose seems fine with diesel and the two products are cross referenced. I kinda got the feeling it was a "legal" type thing where they didn't want to be responsible for a (remotely) possible fuel leak causing a fire and thus injury while using push on fittings. Yet the fittings can withstand 300 psi and I couldnt pull it apart.



Kinda shoot a hole in everything I'd been gearing up for... if its true. Every web site I find it on says its OK for petro based hydraulic oil, hot lubricating oil, and diesel fuel. Hmmmm.

 

[15w40]

If the hose is compatible with diesel then why not add some hose clamps to the push-on fittings? Kind of a belt and suspenders approach to the problem.

 

[Ncostello]

About the only clamps I'd consider are the two ear crimp on type... like on the turbo wastegate hose. I'm not too fond of worm gear clamps. Plus your not really supposed to use clamps with the socketless push on hose. It can possibly cause seepage. I definately have no fears of the hose coming loose. Again tonight I assembled a fitting and put it in the vise. I simply couldnt get it to pull off even 1/16". The hose would break first I think. The tighter you pull the tighter the grip gets. Later on I cut it open and the barbs really put a groove in the liner.



RSnaith said he used the Gates LOC (LOL with fabric braid cover) on the Holley Black kits at one time but the high MTBE fuels (as in California) was stripping it. He stopped using it. On the other hand research shows that Nitrile hose is fairly resistant to fuel oil and MTBE. I couldnt find much on Nitrile vs. MTBE. I'll have to think about it a little more. Gates engineering person really didn't give me the satisfying answer I was looking for. Even if it was bad for diesel he really didn't give me any good reasons.



15W40... you were right! There really isn't enough time in the day to get it all done fast enough.

 

[Ncostello]

Need a little help on this!

Got the bed off today and removed the pickup assembly. So the truck is out of service until I get done. The pressure is now officially on! Tank's real clean inside with no sludge or dirt in it. A couple of specs in there but nothing to get in a fuss about. The inside is white HDPE so its real easy to see anything with just a small flashlight.



I'm not even going to get into all the questions I have about the wild stock pickup assembly. That thing is kinda... strange to say the least. Looks like it was designed to hold fuel during low levels and subsequent sloshing... to prevent air from getting sucked in the line.



Anyway... if a person (me) installs a standpipe, what keeps the line primed? Or... does the VP44 act like your thumb over the end of a straw? Otherwise I'll have a drained line each time I shut off and I'll get air in the system. Not what I want!!! I'm assuming it works as some here have installed plain ole stand pipes already.



I know it works on some diesels. I installed a new standpipe in a Cat application once and it holds prime on its own forever. But thats comparing apples to oranges too.

 

[24VChev]

tanks

I have heard of a few people putting in a fitting on the bottom of the tank. Maybe this wold work better for you.



About the priming thing, if the stand pipe opening remains below the level of the fuel in the tank air cannot get in unless you have an air leak upstream, therefore it remains "primed".



Just a thought





Malcolm

 

[csutton7]

don't be surprised if your pressure goes kaput once you are around the 1/4 tank level and going up and down hills with the stand pipe setup or even quick starts and stops----either you punch a hole in the bottom(like me) or use the stock setup and increase the line size at the top of the OEM pickup unit-or buy one of the setups that changes the size orf the pickup tube in the stock OEM unit-we had to go back to the stock pickup unit after a stand pipe was installed and everything is A-OK now with the truck that we did this to--chris

 

[Ncostello]

There's really no way I can do a bottom fitting. I'd like to, but it's a 2WD and the tank is definately the lowest thing around down there. I'm sure if I ever ran over any road debris, it would knock off the hose for sure with my luck.



I've still got all the stock pickup parts... its just that the little valve and spring is held in place by the membrane type screens, more or less. And the membrane is now gone. I'll have to look at it some more.



The inner 3/8" hose (coiled large one) attaches to the elbow fitting at the top of the assembly. The other end attaches to some kind of cylinder contraption at the bottom of the pickup. I have no idea whats inside that cylinder looking deal. When I look up in there from the bottom of the pickup, all I see is black plastic. Any ideas whats inside that internal cylinder component?



I'll get some close up photos of the whole thing to clarify what I'm seeing. Thanks for the responses.

 

[Ncostello]

More pickup discussion

I've got some great pictures of the pickup assembly that may answer many questions for future bombers... which is what this thread is all about. However the camera battery died and I cant finalize the CD... and the computer I'm using doesn't have a re-writable CD burner so it won't read a unfinalized disk. Anyway I'll get them up shortly. Most of the following (and pics soon) is for those who wondered but never saw anything. Those who have been here before may already know what I'm talking about.



I believe I fully understand how the OEM pickup works. After going to Dodge and looking at a new one, then looking at the $424. 00 price tag... something inside my wallet (or lack thereof) made me re-think my original destructive behavior of yesterday when I cut out every inch of the filter fabric!!! Once you see the pics, you'll also be able to understand that the Dodge/Walbro engineer who designed it deserves an "A"... sort of!



Some interesting data tid bits I have are as follows:



The tank is 72"L x 12"wide x 12" deep with about a 3-4 gallon hump in the back. It does taper to 8" tall at the very front.



The tank outlet (where my suction hose connects to now) accepts a 3/8" ID fuel hose... but the fitting is verified as 1/4" ID. And not a bit over... literally. A 17/64 drill bit will not fit at all. But the outside of the fitting is enough to make a 3/8" line snug... add a clamp and presto!



1/4 tank on my fuel gauge is equal to 5" depth in the tank.



The pickup is exactly 30" O. C. from the back of the tank.



The stock pickup is 3/4" off the bottom of the tank.



And the tank is 14" from the bottom to the gasket surface for the large HDPE nut. The pickup is sprung out longer than 14" so when its installed the pickup inlet is held snug 3/4" off the bottom by the spring action of the assembly under compression.



I rolled the truck back and forth to get some sloshing on level ground. I had that stuff rolling in there... and even with 1/4 tank showing on the gauge... I could not get the fuel to "disappear" from where the pickup will be. A nice hill would be a different story. That may prove useful in further considerations and calculations for what I'm gonna do.



After studying this contraption, I realize what Dodge wanted to do... but there was a much easier way. Maybe I should call them.

 

[TxDieselKid]

Originally posted by Ncostello

There's really no way I can do a bottom fitting. I'd like to, but it's a 2WD and the tank is definately the lowest thing around down there. I'm sure if I ever ran over any road debris, it would knock off the hose for sure with my luck.

This has been a great thread so far.



As for the commit above, I have a 2wd, and the sump on the bottem of my tank is NOT the lowest part, the axle does go lower then the sump. This same sump is being used on the Fords, with great success so far.



HERE is some pics of the sump, i'll try and get one of mine on the truck tommrow.



#ad




Andrew

 

[csutton7]

TDK--thanks for the pics ---interesting --what are the dimensions of that sump



one thing about the OEM pickup is the fuel return dumps into it, thus providing fuel when the tank is low and you're going up or downhill-----chris

 

[Ncostello]

Nice piece Txdieselkid!! Now that warrants consideration. Having the return in the sump would definately prove to be worthwhile with respect to the low level situations. Seems like I read where some ford guys didn't like the return right on top of the suction however... I cant remember. Hot fuel I guess.



I agree a bottom sump is not the lowest thing on the truck but it is the lowest thing for some distance. Its just so wide open... almost as if its a skid plate albeit up higher than the axles. Just a fear of mine I suppose. But that unit looks pretty strong. Maybe a mini skid plate would help. That would be pretty easy I think.



(My photos wont be posted until tomorrow morning... nothing I can do about it tonight. )



Chryslers design that included the fine mesh was a good idea... but lacks in many ways. Its not bomb-worthy and I doubt they intended it to be. But the idea has merit.



Imagine the fuel module reservoir as a pitcher (pardon the simple analogy). The return dumps into the pitcher and keeps that pitcher full at all times. The excess return fuel just overflows the top level and it goes into the tank.



The pickup or feed hose is plumbed to below this so called pitcher and draws fuel off the bottom of the main tank. Surrounding the inlet to the feed hose opening is a volume (or chamber) made of super fine mesh membrane material. I'd say the interior volume of this membrane chamber is about that of a tuna can. So it prefilters the fuel the pickup tube gets. I have no idea what the micron rating is but I simply cannot see the holes... the stuff just looks like transparent wax paper. I think its poly cloth of some type.



Now... at the bottom of this pitcher is a check valve that is held closed by a light spring. If you fill the pitcher completely up... the spring is barely able to hold that amount of fuel. The check valve is also connected to the membrane chamber... such that if the check valve opens it will flood the chamber, and thus the supply line inlet, with fuel. Now the outlet to this check valve is also screened with this mesh so Chrysler wouldn't have any debris getting to the suction inlet.



So when does the check valve operate? Well, I figure it happens when its got a full pitcher of fuel above it (it always does) and the check valve is just begging for a little more help to open. That extra help comes in the form of suction from the lift pump. If fuel swishes away from the pickup assembly leaving it high and dry... that membrane chamber is then placed into a vacuum mode as the fuel inside it isn't able to quickly flow away with the rest of the fuel. Its fine enough to where it doesnt flow through too quickly. Thats a big key here I think. Then the inlet hose sucks the remaining fuel inside the membrane chamber while at the same time the check valve opens and floods the chamber with a somewhat continuous supply of fuel. Remember as it drains the pitcher... the return keeps supplying it so it would take a while before you ran the pitcher reservoir dry... then you'd be out of fuel. But the bet is that the swiching tank fuel would come back at some time and fill the membrane chamber from the outside again.



Sounds crazy I know but I had to get my ideas out of my head. Dont know if my description makes any sense but that has to be how it works and the photos will make all the difference in this crazy explanation using lemonade pitcher analogys.



If my theory is correct... then I've totally defeated this function on mine as I cut out all the membrane material unknowingly. Dodge shows the membrane chamber/filter as a seperate part but they dont sell it that way. Makes me mad cause its easily removable as a unit from the whole assembly.



Sorry for the long post again. And I still dont regret doing what I did. I'll be OK. Besides that membrane it too fine for me to flow good. I think its a decent restriction in some part.



They could have made life easier by simply putting the inlet suction point at the bottom of the inside of the pitcher and putting a one way rubber flapper valve on the bottom of the pitcher to let fuel in from below (main tank) and it wouldn't let fuel escape if the tank pressure on the outside of the pitcher went away. It would simply close as a one way valve. I'm tired now and cant keep my eyes open. Night all and happy dieseling.

 

[Ncostello]

99 Fuel Module Ins and Outs



That link shows what I am dealing with inside the tank.



And this is where its all going down.

 

[TxDieselKid]

Originally posted by csutton7

TDK--thanks for the pics ---interesting --what are the dimensions of that sump



one thing about the OEM pickup is the fuel return dumps into it, thus providing fuel when the tank is low and you're going up or downhill-----chris

It is 5" across, and 2" from where it hangs on the tank to the lowest point. We can put a -10 AN size line in it, which is how mine is set up. We could put -8AN or -6AN or anything else.





Andrew