Guys,
I've parked the truck for the moment, wondering if it's safe to drive or not.
Edge Attitude is showing 0-3 PSI at idle, the same or less at speed.

I replaced the fuel filter to see if that helped. fuel psi went back to 10-12 at idle, then, after about 2 miles, it dropped to 0-3 PSI again.

So, is it bad fuel? I filled up with about 27 gallons 50 miles back.
Is it bad fuel pressure sensor? How would I tell?
Is it a failing lift pump? It pumps like hell after the 25 second key bump test, got at least 1 quart out of it.

Any tips would be much appreciated!

 

Only way to know for sure is with a mechanical fuel pressure gauge while driving. Most likely the lift pump though. Some say it is safe, others say no. I wouldn't trust the VP to what I think is a failing lift pump, I'd get it fixed myself.

 

You should get more like 50 oz in that test..........change the pump.

Bob

 

When you do a bump test is the fuel traveling through the filter?

 

Bump test was done with the old filter in the cannister. I think though, (perhaps someone else can confirm) that the diesel that comes out the drain does not pass through the filter.

Is this the way that lift pumps fail? They work just fine, then the next minute they show real low pressure, then a bit later they show pressure again?

 

Lift pumps are a very common problem. Do you feel like risking a $1300 IP on guessing it is or is not a lift pump???

CHANGE THE PUMP!!!

 

Yeah, you're right. Looks like I'll be replacing the lift pump. I was hoping for an easier answer.

 

Depending on where you have your lift pump, on the motor or in the tank, they aren't too bad to replace.

 

I am activley looking for a 24 valve so I have been reaserching this. I tried talking to an odd gentleman that belongs to our car club and has a 2002 CTD 6spd dually.

I spent over and hour explaining to him the importance of a fuel pressure gauge. He didn't get it. I just gave up on him.

 

Lift pump is pretty quick and easy to change. Just grab one and change it out. You are likely due anyway.

If it's not the problem you'll have the peace of mind that you are running a new lift pump..

 

Here's a TSB at Geno's, describes how to flow test the lift pump. I figure I'll do the test to see what results I get. Anybody have any experience with it?

http://dodgeram.info/tsb/2003/14-002-03.htm

 

Resolution: Did the flow test per the TSB above. Spec calls for 1.3 liters in 25 seconds, this is between the filter and the VP44. Lift pump produces 1.5 liters. Test drove it. 12 psi at idle, 5 psi wide open. I'm gonna run this way for a while, with a new spare lift pump and filter in the tool box. Based on tech discussions I've read on this site concerning VP44 and lift pump operation, I figure I'm good to go. One possible explaination I have for showing 3 psi at idle for a bit after the first filter change is that MAYBE there was some air in the filter that didn't prevent starting and wasn't evident until 5 minutes of run time. On the filter change I did fill the canister with diesel to avoid having to bleed the system, but maybe there still was some air in there. Since the filter I removed was plugged, maybe it was just some crud in the new tank of fuel I recently added. Or, perhaps that lift pump is on it's way out. I'll be watching it. Thanks for the advice guys, y'all are a great source of information!
David

 

My lift pump did the same thing last week. 10 psi at idle, 5 psi at WOT, then at random would drop to 0 psi. If I shut down and restarted, back to 10 psi. Replaced pump last night, seems OK so far.

Nathan

 

I just went through a similar issue, after I installed a Edge kit on my 2002. Before the install, the truck was stock. After install, the fuel pressure readout showed about 2-3 at idle and then would go down to 0 driving. I did a lot of reading online over the past few days, and really started to believe that my LP was junk. But logic told me a couple of things - first, my truck has less than 35k miles and was stock, and second, it was running great. So I called Edge, they walked me through a few things to try and test (make sure that the sensor readout shows about 33psi when unplugged), and then I had a friend go through the air bleed procedure with me to make sure that I knew what was going on. What I discovered was that while I was doing the procedure mostly correct, somehow it slipped my brain that you need to close the banjo fitting before the LP stops the 25 second cycle. We did a bump start / bleed 3 times today, similar to bleeding brakes, and now the pressure is where it should be. In my case, it's around 14-15 at idle, and goes down to 6-7 on level 3 with the Edge Juice/Attitude box.

Just some feedback, since Edge never talked about making sure to close the banjo when you bleed the system. Also, as a side note, the factory service book for my truck says to bleed by loosening the test port (inlet) side, and Edge's book says to use the return side. We used the return side, as we assumed that you would want to bleed out air through the whole thing. Not sure if that is logically correct, but it did work to cure my problem with zero fuel pressure under very light load. And, the truck now makes some more power.

 

My final resolution on this one: Replace the lift pump. Like y'all recommended above. Weird thing though, when I first replaced it, I thought all was good. Drove it for a bit, fuel PSI looked good. Put the pedal to the metal and the fuel pressure dropped to 0 PSI again. Bad lift pump? No. Turns out that the starter bump test can show it build to 13 PSI even if you have a slight kink in the rubber line between the lift pump and the filter. When the VP44 starts demanding more fuel that kink sucks closed and it goes to 0 PSI. Dumb me. I rotated the banjo bolt to the fuel filter about 30 degrees and all is good. So, what it amounts to is that the Edge Attitude monitor did correctly report the fuel pressure, detecting a bad lift pump (hopefully) before it impacted the VP44.