Fuel Pump - Cummins

Aerobaticflyer

Aerobaticflyer

New Member
Mar 24, 2009
263
Bradenton, FL.
Boat Info
390 Sundancer 2005
Engines
Cummins 380's
It appears I may have a failing high pressure fuel pump on one of my Cummins QSB 5.7's and the cost to replace it strikes me as extraordinarily high. Do any of you with experience with this part failing know what is it that would drive the replacement cost so high? Talking aroung $3500!

The diagnostics done on it indicated it was delivering far below the 20,000 psi required thus setting off an alarm. Hard to believe 20,000 psi to begin with.
 
That is part of what makes a common rail system so efficient.......i.e. atomizing fuel under extremely high pressure with very precise timing. At this point, it really doesn't matter what the cost is, you have to either rebuild the pump or replace it and a $3500 estimate for the pump and labor doesn't seem outrageous to me. What makes the cost so high is that this isn't an old diaphram type fuel pump that pushed fuel at 7-10 psi...... It is an extremely sophisticated part manufactured to very close tolerances so that it can generate very high fuel delivery pressures.

If it were an old style mechanical pump, a good diesel service company could rebuild it, but since it is electronic, I don't know if that is even possible outside of the Cummins dealer supply chain. There is a Cummins specialist who is a member here Perhaps he will see your post and offer an opinion.
 
Wow, this makes $300-$400 bill for a gas engine sensor look much more attractive.

Man, when you think that newer technology should help us save money it manages to do just the oposite. However, on more optimistic side it's good thing that we don't hear too often for these pumps to go bad (at least I didn't see too many posts on them).
 
What I'm seeing on another reputable diesel site is that the pumps failing aren't that unusual and what makes them costly is mostly the labor associated with their relative difficulty to access. That said.......I don't see the kind of costs I have been quoted. I have another mechanic looking at it in a few days and we'll see what they come back with......:huh:
 
Aerobaticflyer said:
What I'm seeing on another reputable diesel site is that the pumps failing aren't that unusual and what makes them costly is mostly the labor associated with their relative difficulty to access. ......
Click to expand...

That sucks....now I understand even more why Frank prefers older and manually controled diesel vs newer ones with some electronical components.

I wonder if it's a DIY item if you get a new pump on your own?

I would get 3 quotes (from reputable shops) instead of just 2 to make sure you're comfortable.

Good luck and keep us posted.
 
I would suggest that you find out why it is failing, if indeed it is.... What is the exact symptom that you are experiencing leading you to believe your CR pump is failing? Be precise and explain all..

With many QSB's (30+) in the field that we watch over with 2000+ hours and some with 8000+ hours, we have only seen ONE failure .. It was low hour engine that did not have good filtration before the engine.. He relied on a single Racor..

Send me your engine serial number and some detailed history of your application and I'll see what pops up price wise, etc...

Tony

http://www.sbmar.com
 
imho: Typically when any high pressure pump gets weak it is due to wear. The number one root cause of wear is contamination. New and Old school engines alike. These new common rail systems are more tolerant than ever to self inflicted contamination introduced during routine service. One engine manufacturer that I am very familiar with does not recommend pre filling filters for this very reason. On a common rail system, you want clean filtered fluid to the pump and injectors.
 
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For your professionals, what about fuel quality in addition to contamination?

I live in Tennessee part time and we are having fits in this area with ULSD in newer electronic diesels, particularly Dodge/Cummins and Ford/Navistar. The diesel service company in this area is a Cummins mid-range dealer and he has found that fuel available now needs a lubricity additive to replace the natural lubricity lost from diesel fuel when the sulfur is removed. His customers who regularly use a lubricity additive, just don't have fuel related problems.

The original poster is in a populated area of Florida so I wonder if his marina's fuel distributor is delivering USLD instead rather than maintaining inventories of both ULSD and LSD.
 
fwebster said:
For your professionals, what about fuel quality in addition to contamination?
Click to expand...

Good point Frank. Cats newly engineered plungers are supposed to deal with this. Personally I'm on the wait and see fence. Don't know what Cummins is attempting. Running a lubricity additive in any diesel these days seems the thing to do. With more DPF's showing up, things could get even more complicated!
 
Frank, do you think we might have similar diesel issues in our region (NJ)? What additives do you suggest to prevent the issues?
 
Yes.

What we are seeing in the south is that the fuel distribution chain is not stocking but one "flavor" of diesel fuel. Most here have retail outlets for over the road equipment so they only stock ULSD to avoid the cost of a second set of tanks, pumps, etc for LSD. My own personal experience is that the retailer where I buy fuel....whether it is fuel for equipment or trucks in Tennessee or the boat in Fla......is that they do not know what they are selling you.

I don't take chances. Pumps and injectors are expensive to repair or replace, so I use the Stanadyne Lubricity Additive in every diesel engine I own in addition to a good biocide. I've posted something on fuel management several times so you might want to search it up.
 
Here's an update......second mechanic switched sensors with port engine and we sea trialed and low fuel pressure alarm stayed on the starboard engine (when above 2700 rpm) so it looks like the pump is in fact the culprit. This was after all filters were replaced and tanks and fuel cleaned & filtered.

As background info......I buy 90% of my fuel from my home marina. It is said to be Valv-Tec treated and they go though about 2000 gal / month.....not all that much I'd say. My recent fuel and tank cleaning did uncover some water and algea growth but all was filtered to 2 micron as well as new racor elements and spin on filters replaced. I'm confident my fuel and filters are good now. Since the boat had 318 hrs on it when I bought it a year ago I can't be sure of how the fuel was cared for prior to my purchase. I know the boat was laid up for extended time. Another reason I decided to get everything cleaned so as to start fresh.

Hopefully after the pump is replaced all of my WIF & low pressure alarms will be in the past. I may go elsewhere for fuel to eliminate that as a possible contributor to my issues.

Thanks everyone for their contributions.

Tony - S/N is 46431137
 
Aerobaticflyer said:
Here's an update......second mechanic switched sensors with port engine and we sea trialed and low fuel pressure alarm stayed on the starboard engine (when above 2700 rpm) so it looks like the pump is in fact the culprit. This was after all filters were replaced and tanks and fuel cleaned & filtered.
Click to expand...

What sounds odd to me is the "low fuel pressure alarm". The common rail systems I am only lightly familiar with use two pumps; a high pressure and a low pressure. The low pressure pump supplies the high pressure pump. The low pressure fuel system typically has a fuel pressure sensor to alert the operator of a fuel supply problem, filters/... When the high pressure pump goes out they usually wont even start. What has me puzzled is you are describing symptoms of a fuel supply problem ("alarm on above 2700").

Tony: Is there a sensor on the low pressure supply side of the op's fuel system? Does Cummins monitor the high pressure side for other reasons than timing stratagy?
 
We have seen and decent % of the low pressure pumps give issues, and give off 2 or 3 various alarm codes and running symptoms.. The Pump is under $170 to an end user should you not be under warranty..................Recently, CMD has went to a new design & vendor to try and solve the issue.. The newer pump just came out and looks very similar, but hopefully will give better service percentage wise.. If I could put a number of failures, I'd say 15% of the QSB engines we have installed, have seen a low pressure fuel pump issue with the first 2000 hours--IMO, way too high..

As to the expensive CR high pressure pump, no issues at all in about 60 engines that we watch over closely with many over 5000 hrs except for the very few that did not upgrade their fuel delivery systems to better quality filtration before the engine...


Tony
 
Hey guys, I'm just curious if something I experienced the other day might also possibly be a low pressure fuel pump issue. I was cruising along at about 2200 RPM +- (~28mph, 80% throttle) and had been at that speed for probably 15 minutes. All of a sudden I felt a slight drop in RPMs and my Smartcraft gave me a "IMP Low" Port Engine alarm. I looked it up and went back to a thread I remembered here on CSR and I'm pretty sure the IMP is "Inlet Metered Pressure", which means the fuel pressure was low. I came off plane, shut down the Port engine, started it back up and didn't see the problem again .

I hadn't changed my Racors (each engine has two and I use both) in a while, say 3-4 months of light use (over the winter) so I went ahead and changed them all out. Ran it again today and the alarm did not happen. So I'm assuming it could have been the Racors, at least that is one possibility. If I see it again though, then ruling out the Racors and assuming there is no burst fuel line (which I would obviously see in the bilge, ie. bilge filled with fuel) does that pretty much leave on the low and high pressure pumps? Ie. if I rule out the Racors and it comes back, an IMP error, can I say for sure at that point it's one of these two pumps? Or are there other possibilities? Or am I going in entirely the wrong direction? :)

Thanks,
Jason
 
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