HOHN

Actually, you CAN ask for better cooling. Fuel temps in the tank can exceed 160°. with some cases of 180° being reported with certain fuel setups. How hot is it underhood? This hot or cooler?

I'm under the impression that liquid is a more efficient conductor of vibration than air is. This is because air is compressible, and this absorbs vibrational energy. For an equivalent energy, sonar has more range than radar, because water conducts the energy waves more efficiently than the air does. The liquid does NOT absorb vibrations, at least not in the case of diesel fuel. To get a liquid to absorb vibration (like a Fluidampr), it must be VERY thick, with a viscosity thicker than 40wt oil, not to mention diesel fuel.
True, time will tell. But the reality is that NO ONE KNOWS why lift pumps fail. Yes, we believe that the LP should push instead of suck. But the truth is that it is ALL SPECULATION. NO ONE HAS PROVEN ANYTHING about lift pump failures. In short, we have a bunch of theories and no scientific data-- just theory. Conventional wisdom says that having good FP will keep your VP44 alive. Yet mine died at only 42K with perfect fuel pressure all along!!! How does that jive with the "proof" that VPs die from bad LPs??

I happen to believe that my Scotty Fuel system will help my LP live longer. Proof? Nope! There's no way it *can* be proven with just my one isolated case.


Something to ponder: if engine vibration is so bad, and if sucking fuel from far away is so bad, then WHY DON'T 12Vs HAVE LP ISSUES?? Or is the sucking and vibration only bad for electric pumps??




In the end, I say forget your stupid warranty and fix it right. It doesn't get any more "proven" than a 12V lift pump setup. So I'm gonna keep my stock LP with Scotty's line until I can do a Don M cam and mech 12V LP. THEN, it will be fixed and fixed right, and not until then. Every other wannabe has failed the test: FASS, AirDog, Holley Blue, Product Engineering, Essex, you name it.

In fact, the only electric pump I'm aware of that has been "proven" is the Aeromotive A1000.
jh

staarma

Well...I for one am glad this whole thing blew up in several threads about lift pump solutions. I have had a hard time trying to decide what to do. I for one do not follow the crowd and take peoples word for things just because "that's what everbody else is doing". I like to hear objective and factual results from several different sources. The technicalities about the intank versus the filter mounted pumps don't concern me because I know what I have and it needs replaced pronto. Ditto about the warranty, don't care. I was ready to shell out the money for a FASS because of a few level headed guys hear that I read posts on (Dodgezilla and Coobie) that have done the FASS and reported what I believe is accurate info. The only problem I had is the amount of $ the system costs. I have racked my brain on how a pump would cost the money they want for theirs. Just couldn't do it. From these threads, I learned what the underlying problem is and what conditions the fuel supply should follow and most improtant of all, there is more than one way to rectify the problem. I have checked around and really started digging with this new found info and I have a solution that should be here today that will be installed by me this weekend. I'm looking forward to no more bad stutters on the top end at wide open throttle with the boxes turned up and now I can continue down the road of bombing heaven without worrying about one more problem to overcome or how long my CP3 will last. Thanks to all who contributed to these threads. Sometimes it takes p'd off or toes getting stepped on to get to the meat of the matter. This is how we really learn.

bluebull

trik396, stock was the key word. I was asked why I knew some things about cummins engines and gave an answer.

superduty, the filter statement is just stupid.
Your attitude is exactly why we don't just shut up and listen.
That and is easy to pick apart your system and use your parts to make a proper setup.

What do you have some crystal ball about the in-tank lift pump, give it time.

Your the one that is talking out both sides of your mouth. I'll give you an example if I have time before I have to go back to work.

Your not telling us anything new about DC knowing the have problems with their lift pumps. They are the ones paying for the warranty.

You say we are bunch of know it alls. Everything you have brought to the table has been hashed over many years ago, including your walbro pump.

You say the pump differential is the same accross the pump. Yes but now put a restriction in line such as the line it self, length of line, fuel filter, return restriction.

You say. we know why the pump dies, the motor burns out. Ah, take a few apart to know for sure. I have seen stuck vanes, broken shafts, burned out armatures, worn vanes from debrie. Listening to the sound can give many differnet diagnoses. I have heard pump running with zero psi.

Hohn,
Yes we can ask for better cooling but it would take more of setup than what we have.

You are absolutly right about sound waves.

Your absolutly right about speculation, the reason we try different things to over come a bad effect, DC's new in-tank compared to engine bay ones.

I was under the impression it is isolated to the electric pump, The reason the 12V don't have as many problems.

Your right again about the other aftermarket guy having failures. The reason I debate superduty so as maybe there can be a setup that will not cause people problems.

staarma, Your absolutly right, and for modified your absolutly right again. New truck with 7/100,000 warranty not. Last I checked this was the forum for non modified trucks. If some one want to put on an after market part thats their choice, at least they will be informed as to some of the negative effects. You know not everyone that reads these threads are mechanically inclined. Some can not even change their own oil. That same guy reads these threads and WOW I better change that lift pump. Now a few months down the road he has engine failure, he takes the truck back to the dealer for service. Service rep inspects truck, oh oh, you have gone over the specs or changed the parimeters of what the truck was designed for. Truck owner is very ticed off because now he is imbarrassed about is lack of knowledge because no one warned and even more ticked off because he has to fit the bill.

Time to go to work.

Berak

I've been reading all these lift pump threads but I don't understand why a decent electric pump can't be plumbed inline that is fairly cheap and replaces the filter mounted unit or the in tank model. The factory system doesn't have a pressure regulator or a CP3 bypass, why complicate the system?

bluebull

I really shouldn't type when I'am pressed for time. I want to rereply to HOHN.

160-180 degree fuel, under what conditions, 1/4 tank of fuel running dyno runs in an enclosed building or what. I hardly think you'll see those kind of conditions in real world testing. I don't doubt that the fuel temps can get that high but for what % of the actual run time of the vehicle. The only conditions that would come close would be driving low on fuel on very hot day. That same very hot day what do you think the under hood temps are?

Vibrations, What vibrations like the ones encounter on the engine is going to be encountered in the fuel tank?

bluebull

Berak, there is, superduty has one once all the bugs are worked out of it. www.summitracing.com has one wiring harness, pump, relay, everything needed for around $130.00 Some others have been mentioned in this post.

This thread was started more for in-tank evaluation, some times thread get side tracked.

trik396

Bluebull, I meant no disrespect. And I understand your answer. I think you and Superduty should just agree to disagree and call it a day. We are all here to help. Nothing more. Life is to short.

djbikeman

Not that it matters much at this point in the thread, but DC verified today that the in tank lift pump is covered under the 5/100 Cummins warranty.

Have a nice day everyone.

coobie

DITTO,I feel the same way.Why in the Hell can,t we just learn from each other.coobie

TurboTed

I learned a lot from this discussion about lift pumps. (Entertaining too!! )

windyr

I am skeptical of in tank lift pumps, even though they can be good and reliable. They are nearly always impossible to change on the road and at least inconvienet in your home garage. Most require draining the tank, disconnecting the electrical connections, fuel lines and fuel filler and vent system then dropping the fuel tank in order to access the fuel pump. They tend to be expensive. The replacement fuel pump module for our 97 chevy Astro van is about $400 for parts. Another $200+ to change it at the dealer.

Our 97 Chevy Astro is on it's 4th pump at 105K miles. The lift pump is by far the least reliable component on our Astro. A chassis mounted pump like my Puegeot has (similar performance specs) is far more desirable and in my case far more reliable (origional pump failed at 225K miles) and takes 20 minutes to change.

I will be my own repair station for my Dodges lift pump and it will not be getting the in tank "solution". This forum, especially Superduty's exlplanation of the fuel system and it's requirements make me totally confident that my solution will have suitable reliability and much better servicability than the factory in tank pump patch. The last thing I want is a "factory improvement" that would force me to go to a dealer if I have a simple pump failure on the road.

Regards,

Jim B

abc4yew

Guys, Superduty is stand up guy who's on the ball. Blueball has one valid point. The lift pump set up on these trucks is second rate. Cummins power, lada fuel pickup. If the fuel is dirty passing it through the filter will get it out of the fuel ( and storage) system. If it is clean it'll just pass through the filter. The stock system circulates the fuel constantly through the stock filter. The FASS does it through 2 bigger filters. The stock pick up in my tank was full of crud that would never be filtered out. I'm 99% sure that is what wounded my lift pump. My FASS fuel pick up is a piece of steel tubing so all the crap in the tank can make it to the filter where I can get rid of it. People that replace the stock lift pump without dropping the tank and checking out the fuel pick up are negligent. The best warranty is prevention and diligence. If you are worried about adding an external after marked lift pump having a negative affect on your warranty talk to your warranty provider, your D/C dealer. If you don't have a good enough relationship with your dealer to talk about such things then yah you will have warranty problems. Don't forget to take off the 66 turbo, the TST stacked with the EZ and downloader, the super mondo air intake and the 5 inch exhaust before you take the truck in for warranty service. You don't want to lose the warranty on your a/c, power seats, or stereo. ks

CRXsi

I keep hearing the argument of forget the warranty it will be OK...Assuming one had a good relationship with their dealer and their dealer was OK with altering the fuel system without denying warranty on other fuel system parts (ie fuel injectors, CP3, etc) then I ask how many people have had lift pumps or other fuel system parts fail in a location where they can take it to the dealer they have a good relationship with vs how many fail on a trip towing a trailer or just plain many miles from home and have to go to a dealer they aren't familiar with? This is when it would happen that you would be told "too bad" repair is now out of pocket...which can ruin a holiday or trip pretty fast! I agree there are better systems out there and it would be wise for preventative maintenance, but at the same time I partially bought a new truck for the warranty so that there would be no unexpected expenses that can ruin trips and holidays. I unfortunately cannot at this time justify potentially voiding my fuel system warranty and therefore will likely have to go with the intank set-up if mine fails so that I can be assured that DC will cover any other fuel system component if something else goes wrong...if it hasn't been altered than DC has a very hard time denying warranty, if it has been altered...it could go either way unfortunately.

I agree with lets give the new lift pumps a chance to see what happens. It is unlikely that DC would make a retro-fit to a worse design as even if the part is cheaper there is obviously more labour involved, which eliminates the argument of it is just cheaper for DC...rarely will a manufacturer make an amendment to a part in such a major way like this if it is not going to be benefitial...lets give them the a chance to prove they have possibly improved before we completely trash the newer set-up.

bigblock2stroke

I agree completely. Good post.

Barry St John

Yahoo, this is better than Jerry Springer and I'm a 2nd gen guy looking for answers. I just want to say to all of you that I have learned a ton of hard information from all of you. We all have our ideas that we have put alot of thought and effort into and good results and information comes from all of this discussion be it hot or cold, part truth and theory, or all of either of the above!! The very act of trying to prove the other guy wrong sometimes brings information that leads to the best solution at the comfort level for a particular individual. I like Vulcan's approach so I can use easy to obtain parts and improve on the origional design but I can see that ultimately some of the other approaches are probably more reliable in the long run. I just don't want to be out in the sticks somewhere with limited access to parts and have a problem. Again kudos to all of you and please continue to share what info you come across be it hard facts or theory. I'm still on the learning curve so don't have alot to add but when I think I can jump in the middle of things I will.