Ah, if you read my post I was confirming your information that you do need a pressure relief of some kind.

Are you positive about high pressures will not effect the CP3? I was told high pressure going into the CP3 from the lift pump will damage the seals and thus it does not like high pressures.

 

"Are you positive about high pressures will not effect the CP3? I was told high pressure going into the CP3 from the lift pump will damage the seals and thus it does not like high pressures."

Yes, I am sure. I drove my truck around for a day or so at 60+ PSI until the filter housing lid cracked. No ill effects on the CP3.

If you would read my "Feeding the CP3" post you'd see that the CP3 has a gear pump feeding it which will handle just about any supply pressure you throw at it. Its a positive displacement gear pump after all. Furthermore, the internal pressure inside the CP3 is 80 to 180 PSI, so a little electric lift pump at 60+ PSI isn't going to hurt a thing inside the CP3. The design pressure on the seals is probably 200 or 250 PSI.

BTW: I say 60+ PSI because my lift pump was stalling. It will push 100 PSI on the verge of stalling. Peak pressures to the CP3 were probably 100 PSI. With no ill effects to it.

Who told you that high supply pressure would damage the seals in a CP3 ? What was the reasoning behind that ?

Really, people, I don't have anything to prove by writing this stuff. My truck runs great. I don't have a lift pump or CP3 issue.

I was disheartened to see people having trouble with their lift pumps/CP3s and that is why I said anything in the first place. Actually, someone sent me an email asking about power issues which I thought were lift pump related and that is why I wrote the first article to begin with. I went through all the CP3/lift pump investigation when I put the Cummins in my truck back in July and thus it was easy for me to write up what I had learned and figured out, contributing something back to the group.

If I remember correctly the problem with that truck was lift pump related. Using an aftermarket pump that had failed.

I'm sorry if what I contribute doesn't match the common knowledge. I'll leave it to the group to reconcile the two.

It is a crying shame to see the reputation of such a great engine tarnished because of lack of adequate fuel supply.

 

Are any of these issues covered under the 100,000 mile warranty ?

 

Maybe I came off wrong, if I did I appologize. I, like you, am only after what does and does not work. If some one makes a statement about some thing, I like to know what kind of character is making them. I have read some of your posts in the past, along with many other peoples, it some times takes alot of decoding to figure out who is more correct. I am mechanically inclined, work on all my own vehicles, have 2 years of mechanics school from back in the late 70's but did not persue that field so did not keep up with modern day technology but the basics are not much different. I was selected in high school by a panel of mechanics, dealership, and local school to go to the national trouble shooting shot out. I in know way claim to be any thing more than a back yard mechanic. So you see when some one makes a claim I like to investigate the why's and how come's. Sorry if I offended you.

I guess I was relating to the VP44 in relation to fuel pressure entering the Main pump but I was sure I had read on here and other boards that the CP3 didn't like them either.

It's good to know that if this lift pump takes a dump I'll just install a pusher on the frame rail like I did with my 99 CTD. Thanks for info and keep up the good posts.

Ron

 

https://www.dieseltruckresource.com/...ad.php?t=78702

 

I do think Bosch specs a max inlet pressure ( I think its 16psi, but it was awhile back that I was told this).

I also think SuperDuty is right. The problems are all related to the lift pumps. The CP3 (and HPCR in general) is a vast improvement over the VP44 system.

I have seen several dyno engines run 24psi to the cp3 for over 3000 hours of durability testing (high loads) without any cp3 failures.

Its' a catch22.

You install a high flow aftermarket lift pump and fail the cp3 (or other fuel system component like injectors) and you will probably not get it warrantied.

However, you are less likely to fail anything after installing one because the root cause is the lift pump.

Easy decision in SuperDuty's case (like he has been trying to tell everyone), because he is his own warranty).

If you still have a warranty, I recommend waiting until you don't have one before modifying the fuel system.

 

"You install a high flow aftermarket lift pump and fail the cp3 (or other fuel system component like injectors) and you will probably not get it warrantied."

I highly doubt that DC would disallow warranty because of installing a better fuel pump, especially a Walbro.

"Easy decision in SuperDuty's case (like he has been trying to tell everyone), because he is his own warranty)."

I was told that if I pushed the issue I could probably get some warranty on my engine. However, I don't expect that I will need it.

"If you still have a warranty, I recommend waiting until you don't have one before modifying the fuel system."

I don't. Look at the fun some of the guys on this board are having with lift pumps. 3x in the shop. Trucks quit on the road. DC unable to diagnose the problem.

 

I see what you're saying but everyone one of your statements above are hardly like having it in writing.

People will tell you whatever you need to hear to either get you to buy something or get you to leave.

 

Couldnt one install a fuel pressure guage that feeds the cp3, and if it reads really low then a pusher pump would be the next step?

 

[QUOTE=Superduty
I highly doubt that DC would disallow warranty because of installing a better fuel pump, especially a Walbro.[/QUOTE]

I can guarantee that if DC finds out you will be denied warranty, been there done that. It's up to the dealership to turn in some one with after market parts. Like I was told by a dealership," do you think we are going to jeapordize a multi million dollar dealership on one claim"?

Some dealerships will say that they won't turn you in for installing aftermarket parts. Question, what are you going to with to your warranty if you need to take your truck to another dealership or break down on the road away from home?

I will agree your right on installing something easier to replace and possibly more reliable but I would wait until my warranty is gone.

 

There is a difference between modding an engine for purposes of increasing performance and modding an engine to make it live or fixing an obvious defect that will cause problems later on.

What are these guys with leaking CP3s and engine knocks supposed to do ? It is obvious that DC is having a very hard time with this issue. Installing a Walbro and bypass seems like a very good solution to the problem.

Cummins ultimately warranties the engines. They spec that the engine needs clean fuel at an adequate flow. I don't think there is a court in the world that would rule against an owner taking the fuel supply situation into their own hands. Hopefully DC doesn't allow it to get to courts in the first place. I think it is incredulous that DC has had lift pump problems on the 2nd gen AND 3rd gen trucks. Tisk, tisk, tisk.

 

superduty says---There is a difference between modding an engine for purposes of increasing performance and modding an engine to make it live or fixing an obvious defect that will cause problems later on.---

Not in DC's eyes, beleave me I fought with dealership, DC, arbitration.

superduty says---What are these guys with leaking CP3s and engine knocks supposed to do ? It is obvious that DC is having a very hard time with this issue. Installing a Walbro and bypass seems like a very good solution to the problem.---

According to DC's warranty, let the dealership and DC take care of it. I know it can be a pain in the ars, but if you play you pay.

superduty says---Cummins ultimately warranties the engines.---

No, dodge warranties the engines.

superduty says---They spec that the engine needs clean fuel at an adequate flow. I don't think there is a court in the world that would rule against an owner taking the fuel supply situation into their own hands. Hopefully DC doesn't allow it to get to courts in the first place. I think it is incredulous that DC has had lift pump problems on the 2nd gen AND 3rd gen trucks. Tisk, tisk, tisk.---

That's the whole problem, DC has alot more money and lawyers retained then I or most everyone.

Don't get me wrong I know where your coming from and some thing has to be done but the in-tank pump has not been out long enough (a little over a year) to see if it is viable solution or just another band aid. I have only heard of one in-tank lift pump report going bad and it had more to due with the mounting in the tank than the pump.

 

Give me a break. Its a friggin lift pump ! All it can do is properly fill the CP3. What is the problem/harm with that ? You can probably buy an industrial ISB in about 20 different vehicles. Every one uses a slightly different fuel pump configuration, none of which will harm the friggin engine if they deliver it enough clean fuel. And Cummins warranties them all.

This is why I put a Cummins in my Ford rather than buying a new truck. Dealers. Warranty. Headaches. All new trucks have issues. I know all the issues with my SD. I put the engine in back in July and I haven't looked at it since. It purrs. And I don't ever take it to a dealer to have them fix something that should have been right in the first place. I am my own warranty. I saved about 20K versus buying a new truck. My truck didn't quit over Christmas like some others did. I know every part of it. I can fix anything that goes wrong with it in about an hour because I built the thing in the first place.

I could buy a Cummins engine directly from Cummins. They will give me an application manual and in it they will specify the cleanliness, flow and temp. of the fuel I need to feed that engine. End of story. But these OEMs are a different story, or so I am told. The thing that floors me is that if they had done the lift pump properly in the first place we wouldn't even be having this conversation.

You've got a great truck with an outstanding engine handicapped by a friggin fuel system designed to feed a 4 barrel carb rather than a CP3. And not many people at Dodge seem to understand the implications the CP3 or how to feed it properly.

How the heck did I get dragged into this whole mess ? I don't even own a Dodge.

And Cummins ultimately warranties the engines. And Bosch ultimately warranties the fuel system. Dodge just just happens to the be warranty depot you deal with.

If there does happen to a warranty issue with Dodge because of using the Walbro fuel pump, I'll never, ever, ever buy a new truck again. I'm already planning an F450 with an ISL. Cummins WILL warranty that engine in that application. Lets see Dodge, Ford or Chev touch that.

 

Not for the engines in the Rams. Cummins sells Dodge complete engines without warranty. A Cummins shop can't/won't do warranty work on the CR motors because they can't read the ECMs anymore. DC carries all the warranty load on the powerplants of these trucks now.

 

Superduty, did you check with the fuel filter manufacturer to see what kind of pressure it is rated for? That is the only problem I can see with your setup diagram. The higher pressure and flow may compromise the filtering and water stripping abilities of the filter setup.