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2001 Dodge Ram 2500 SLT Laramie 4x4 Automatic.
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Discussion Starter · #1 ·
Hello Everyone,

I have recently been doing alot of upgrades to the truck. Not to long ago I had my lift pump go out right after I bought it off the previous owner. So I already had an idea my Vp44 was on its way out. So I added a new improved Carter Lift Pump in addition with a Quadzilla. Once I tapped the Vp44 the 0216 code came up. The reason for putting stock Carter was I was waiting on the Glacier Diesel Fuel Boss to arrive . So couple weeks later I added Fuel Boss and new Vp44. Now my issue is that I only have 5-6lbs of fuel pressure at idle on both gauges. If i pull out of driveway coasting it goes up to 10-12 and at WOT I get around 16-18. Which is still low at all points compared to what the Fuel Boss should be doing. I have been troubleshooting it the last couple days and clamping off the 3/8 lines in areas to figure out where issues are at. I clamped the (fuel boss return line) bypass off , disconnected stock lift pump and clamped off near check valve to stop the flow to stock lift pump. That would only leave fuel to enter through supply feed line to fuel boss and have to return to tank once through vp44. After both those being clamped off it was still 5-6psi no change. So i decided to clamp the supply line very slowly that goes from fuel boss to the vp44. And the pressure on 1 gauge starting shooting up in pressure and the one near vp44 started dropping dramatically. I feel like my my system is not holding fuel pressure because it is getting sent right back to the tank. What could be this issue? Here is a picture of how i have my lines setup.
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There is an overflow check valve on the fuel return line from the VP44 to the tank. Restrict the fuel return line from the VP44 to the tank and see if the pressure rises and both gauges.
 

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2001 Dodge Ram 2500 SLT Laramie 4x4 Automatic.
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Discussion Starter · #3 ·
There is an overflow check valve on the fuel return line from the VP44 to the tank. Restrict the fuel return line from the VP44 to the tank and see if the pressure rises and both gauges.
Hello 2002CTD,

How would you suggest I do that? The return line is a hard line all the way to the back firewall area where it goes into a “T” of some sort and it looks like nylon hose and goes down towards the frame
 

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Hi! The fuel return line from the VP44 (#8) goes to a T fitting near the firewall (#3) which connects to the return fuel line from the banjo fitting on the back of the head (#9). You'll need to temporarily disconnect the fuel return line to the tank (#7) and rig up a rubber line between #3 and #7 that you can restrict.

OR

You can forgo the troubleshooting, make an educated gamble, and simply replace the VP44 return line check valve (#6) to see if that solves your pressure problem (which it may not).
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2001 Dodge Ram 2500 SLT Laramie 4x4 Automatic.
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Discussion Starter · #5 ·
You can forgo the troubleshooting, make an educated gamble, and simply replace the VP44 return line check valve (#6) to see if that solves your pressure problem (which it may not).
They sent me a new Check Valve for the Reman Vp44 I just installed on the truck. I thought it was the problem possibly so i switched it with my old valve and there was no difference with either.
 
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Multiple duplicate threads on the same issue is not good forum etiquette.

My previous reply is in your other thread on this topic.

Have you contacted Glacier Diesel to get their thoughts?
 

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Discussion Starter · #7 ·
Have you contacted Glacier Diesel to get their thoughts?
Hello Stealth,

This is another issue i’m dealing with concerning a different problem compared to other post. I did contact them and was actually troubleshooting with Richard for multiple hours yesterday. It lead back to the injection pump. Only thing I wasn’t able to trouble shoot was clamping off the return line from the injection pump because I have a solid line going to the firewall. We clamped off the line for stock lift pump and return line from Fuel boss. Once i added a slight clamp to the line between the Fuel Boss and the vp44 the idle pressure shot up on one gauge near the pump to 15 or so and climbing and the gauge near vp44 dropped to 1-2. So it looks like the Fuel Boss is pumping the right fuel pressure but its loosing it somewhere in the system. And its looking like something in the vp44 or after
 

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Here is a thought to another approach. Temporarily bypass the fuel filter and run the supply line from the Fuel Boss directly to the VP44, and clamp the remainder of the Fuel Boss return line before the bypass valve. That should eliminate every variable except the VP44. See what your pressure reads then.
 

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Discussion Starter · #9 ·
Here is a thought to another approach. Temporarily bypass the fuel filter and run the supply line from the Fuel Boss directly to the VP44, and clamp the remainder of the Fuel Boss return line before the bypass valve. That should eliminate every variable except the VP44. See what your pressure reads then.
What issues would I have with it going through the filter? I clamped off the before the bypass already and it didnt make a difference on pressure.
 

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Who knows? That's the point. You don't know where the problem is. Eliminate as many variables as possible. You could also take the Fuel Boss pump out of the loop and run just the Carter to see how the pressure behaves.
 

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Discussion Starter · #11 ·
Hello Everyone, sorry its been a bit. Just wanted to update everyone on my current observations of what is going on. So to start, with the entire system hooked up I get 8 psi at idle and at WOT I get around 15 psi. Which is sufficient enough not to kill a Vp im assuming but its still not the idle it should be at quoted by GDP. Also, if i disconnect the harness to the stock lift pump my pressure is only 2 psi at idle. Any ideas?
 

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First off, that is backwards. FP should drop at wot, not double. Second are you running fuel through 2 or more lilt pumps, probably one not working?
 
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Hello Everyone, sorry its been a bit. Just wanted to update everyone on my current observations of what is going on. So to start, with the entire system hooked up I get 8 psi at idle and at WOT I get around 15 psi. Which is sufficient enough not to kill a Vp im assuming but its still not the idle it should be at quoted by GDP. Also, if i disconnect the harness to the stock lift pump my pressure is only 2 psi at idle. Any ideas?


The Glacier Diesel Fuel Boss system has been around for quite a while.
The mechanical pumps are not popular but always excellent feedback on them.

8PSI at idle and 15PSI at WOT (2800rpm?) would be perfect for a common rail Cummins.
That's the advantage of a mechanical fuel pump, low pressure at idle and higher pressure at high load/high rpm and lots of volume.
What range of fuel pressure are you aiming for with your VP44 engine?


However when you you unplug power to your electric fuel pump the fuel pressure should not change.
That Hobbs switch is set to about 5PSI, the electric fuel pump should not even have power when the engine is running and the Fuel Boss is turning.
So something is definitely not right there.






You mentioned that if you blocked the return line to the tank, the pressure from the Fuel boss goes way up.
This tells me that your Fuel Boss pump appears to be ok.

2002CTD mentioned that the VP44 also has a return line that is not in the above diagram and that you were not able to block that return line.
Blocking that line seems like a good idea to rule out the VP44.

The check valve in-line with the electric lift pump could be the issue. I would unplug the lift pump and block that line,
effectively eliminate the electric lift pump.
If the check valve is leaking fuel when the electric pump is off, it will bypass pressure from the output of the Fuel Boss to the input of the Fuel Boss.
The truck should start without the electric lift pump and then the Fuel boss should start providing fuel.

That bypass valve is really a pressure regulator right? It likely has a spring and pressure is set by shimming the spring.
Take it apart and check it out. I can't see it failing unless it has debris in it.
 

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Discussion Starter · #15 ·
The Glacier Diesel Fuel Boss system has been around for quite a while.
The mechanical pumps are not popular but always excellent feedback on them.

8PSI at idle and 15PSI at WOT (2800rpm?) would be perfect for a common rail Cummins.
That's the advantage of a mechanical fuel pump, low pressure at idle and higher pressure at high load/high rpm and lots of volume.
What range of fuel pressure are you aiming for with your VP44 engine?
Yes, GDP is a great company and ive never heard nothing but good things about their fuel boss that’s why I chose to go with their lift pump. I’m looking to get the fuel pressure they said should be getting produced by their product: 11-16 psi at idle and 18-23 WOT. Instead of the 2 psi at idle im receiving at idle.

However when you you unplug power to your electric fuel pump the fuel pressure should not change.
That Hobbs switch is set to about 5PSI, the electric fuel pump should not even have power when the engine is running and the Fuel Boss is turning.
So something is definitely not right there.

This tells me that your Fuel Boss pump appears to be ok.
Right now I’m not receiving proper pressure with the Carter lift pump disconnected (2 psi at idle from fuel boss only) So from my research my truck is only get the 8 psi at idle because the hobbs is kicking on and using the Carter to get sufficent enough pressure at idle.

2002CTD mentioned that the VP44 also has a return line that is not in the above diagram and that you were not able to block that return line.
Blocking that line seems like a good idea to rule out the VP44.
Yes, I haven’t been able to do that because my vp44 return line is a hard line and when it finally turns into a soft line its nylon which i cant clamp. So i recently picked up some fittings to go from from the vp44 return to a line im going to drop into a bucket. See how it flows out and ill try clamping off and seeing if pressure changes.

The check valve in-line with the electric lift pump could be the issue. I would unplug the lift pump and block that line,
effectively eliminate the electric lift pump.
If the check valve is leaking fuel when the electric pump is off, it will bypass pressure from the output of the Fuel Boss to the input of the Fuel Boss.
The truck should start without the electric lift pump and then the Fuel boss should start providing fuel.
I have already clamped off that line going to the stock Carter lift pump and saw no pressure increase. The truck starts fine with the electric lift pump unpluged just only has 2 psi at idle.

That bypass valve is really a pressure regulator right? It likely has a spring and pressure is set by shimming the spring.
Take it apart and check it out. I can't see it failing unless it has debris in it.
Correct. I have already taken it out and cleaned it and also have clamped off that whole return line with it disconnected to confirm no fuel was exiting through that line and pressure remained the same.
 
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Well, you have covered nearly everything. And you have talked to Glacier Diesel already.


Reading all of this again..

Although you are getting 15PSI with both pumps running, have you checked if the fuel tank supply line or the fuel tank cannister is restricting fuel flow to the Fuel Boss pump?

The truck doesn't have a retrofitted in-tank fuel/lift pump does it?


If you clamped the the return line in that diagram at the return line bypass/regulator and you still have low fuel pressure, and there is no input or supply issues from the fuel tank, that pretty much means something is either up with the VP pump or the new Fuel Boss mechanical fuel pump is failing.

Hopefully someone else has some other thoughts.
 

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Discussion Starter · #17 ·
Just an update. This guy on the 2nd gen facebook group is having the same issue but with a electronic pump. Can get past 5 psi. Everyone commenting is leaning towards check valve/ overflow. It would be wierd if both my valves could be bad? Here is video-

 

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Sory about earlier, Did notrealize you were talking about a mechanical pump. I wish I could help bu do not know about them or why you or somebody installed one. Have you considered going back to electric?
 
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