Leaderboard

"FUEL tank" progress and stuff in a booth!

I think the wires that you are referring to are for the fuel heater and water-in-fuel sensor. You may set a code if they are disconnected, but I don't think it will affect driveability. I think you are on track with verifying good electrical connections between the battery, the ECM, and the PSG on the VP44. "Volt Drop" + "Injection Pump Battery Voltage" seems to equal 14.00 volts, give or take a couple of hundredths on your graph of over 800 reading covering a 10 minute span. On some readings where the voltage is low (10.9 for example) adding the "Volt Drop" doesn't bring it to the 14.00 volt value. This could be because there is a split second recording delay from one reading to the other. I have a scanner, but I don't know if it will display voltage at the injection pump. I will give it a test tomorrow. John

APPS (accelerator pedal position sensor) on the Cummins. When the APPS becomes output signal becomes intermittent as it ages, a specific code is usually set and the engine typically goes right to idle - referred to as "dead pedal". The dead pedal lasts for about 10 seconds or so, then goes back to normal until the next event. The photo below is from one of your earlier posts. I would be specifically concerned with re-checking the voltage to the injection pump. Voltage falling down to 9.5 volts could easily cause intermittent operation of the fuel solenoid valve in the injection pump resulting in random injection events not happening. This does match your symptoms. John John

Like me, I use a 150-amp circuit breaker, and it can be reset at any time without the need to carry a second fuse in case of failure.

So.. they shipped it GROUND and took 7 days to get to me from Utah??? go figure... The part number is: p500-50-a-e4c and when it was available was a $5 part.... I'm going to go on and use the one I received for $90 +plus shipping and tax ($120).

Absolutely. Reading the following may help you feel more at ease: I have owned my truck since new and it currently has logged 402,000 miles on the odometer. Odometer 66,000 miles August 2004 - First injection pump set a code P0216 ( a death code for the VP44). Odometer 87,000 miles August 2005 - Injection pump replaced with re-manufactured unit under warranty. Lift pump relocated as an in-tank pump application (also covered under warranty). Just prior to replacing VP44 injection pump, I monitored lift pump pressure because the word back then (similar to what is now) was that if you don't have 14 psi lift pump pressure, you are going to kill the VP44. So, I drove my truck for a week (250 miles) monitoring lift pump pressure. It operated within factory specs flawlessly and maintained 6 psi at wide open throttle at 2500 rpm. After the replacement of the VP44 injection pump and the replacement / relocation of the lift pump as an in-tank lift pump, my new lift pump pressure was 6 psi at idle and 3 psi at wide open throttle - yes, 6 psi and 3 psi! I was not concerned because by then I had learned much about the true operation of the VP44 fuel system. According to all of the diesel forums, I should have mutilated the VP44. But, that didn't happen..., and it still hasn't happened. Odometer 250,000 miles April 2016 - Install Smarty tuner and set for mild tune. Odometer 251,000 miles April 2016 - Replace in-tank lift pump (not because of failure, but to have more readily serviceable frame mounted used FASS lift (65 gph). Note that the re-manufactured VP44 has logged 164,000 miles with maximum fuel pressure at 6 psi. Should be dead now, right? But, alas, it isn't. FASS lift pump - 12 psi at idle, 6 psi WOT at 2,000 rpm Odometer 303,000 miles December 2018 - Replace original injectors with RV 275's Odometer 402,000 miles - November 2025 - Now have logged 315,000 miles on re-manufacture VP44. Should be dead by now - right? But, again, it isn't. I would like to note that this truck has never received fuel additives, nor 2-stroke oil to the fuel. Also, I would like to note that this truck has done lots of work covering thousands of miles at 20,000 lbs gross combined weight crossing lots of mountain passes in hot summer conditions. Hope this helps. John

It is true that the overflow valve is regulated at 14 psi. However, this pressure (and the fuel return flow provided) has no correlation to lift pump pressure. Your statement here is misleading. I do agree that the overflow valve will be closed when fuel pressure that the overflow valve senses falls below 14 psi. However, the fuel pressure that the overflow valve senses is provided from the flow of the VP44's internal fixed displacement vane pump, not the lift pump. Consequently, the volume of return fuel through the overflow valve is the same for a given engine rpm and load whether lift pump pressure is 5 psi or 20 psi. The VP44's internal fixed displacement vane pump's flow is regulated to well above 100 psi. This is why the 14 psi overflow valve opens immediately when the engine is started. It never closes until the engine is shut off - regardless of lift pump pressure. Since the lift pump and the VP44's internal fixed displacement vane pump are plumbed in a series circuit, the volume of the the internal vane pump cannot be changed by lift pump pressure. The volume can only be changed by changing engine rpm. In the past I have posted the results of extensive testing by others (using a flow meter in the fuel return circuit) that clearly supports what I am saying here. This testing was performed in April of 2001 (before any of us even owned our trucks) by a few Turbo Diesel Register members. About three years ago I performed similar tests, as well. The results showed that fuel return flow remained the same, even when the lift pump was turned off and bypassed. I post this information in hoping to give a better understanding of the relationship between the lift pump, the internal vane pump, and the overflow valve operation in the overall VP44 fuel pump injection operating system. John

ISSPro EV3 gauges give both functions electronic gauge with Bluetooth ability to reprogram any settings in the gauge. Lights (color), warning color lights, set range of warning, much more. Might take a look at those.

Yeah @Tractorman is right. I just caught @Sycostang67 same thing.

Unless you are absolutely set on having a gauge readout, there is the option of using just using a low pressure warning light. I have used the adjustable LEFOO LF20 pressure switch for years. It is my personal choice because the only thing that matters is that there is always positive fuel pressure at the VP44 inlet. The actual pressure value is unimportant. The activation of a LED warning light will catch your eye more readily than a low reading of a fuel pressure gauge. This particular pressure switch has a range of 0.5-150 psi and comes preset at 10 psi. It is compatible with oils and diesel fuels and it is very easy to adjust to a custom pressure value. The cost is under $40 from a variety of sources, including Amazon. You can easily wire in a LED light at a location of your choice. John

But..., before you replace any parts - make sure the transfer case shifter is NOT in neutral. Just sayin'... John

Everything you wanted to know about the VP44 Injection Pump but were afraid to ask. I don't know if these guys do rebuilds or what but he knows his way around the pump:

My cruise control light was always staying on, but the fly-by-wire cruise didn't work. After much problem solving, I finally took the 2001.5 Ram 2500 6 speed diesel to the dealer. Trust me, it wasn't my first choice. Anyway, they told me that the PCM didn't know that I ever had a cruise control equipped truck. The tech claimed that part of the PCM hard drive was dead. The dealership ordered a PCM, but somewhere along the line there was a mistake and they received a PCM for an automatic transmission. They didn't install it. Instead, I ordered a PCM from NAPA for about $450. The PCM came in and the dealership agreed to install it, labor free, since they'd screwed up so many times previously. So, they installed it. Then I got a call saying they still couldn't get the cruise to respond and had determined it was the instrument cluster. Cha-ching! The dealership tells me they can get a new cluster for $790 plus core deposit. I decided I'd buy from O'Reilly who wanted $330 plus core deposit. Well, it was supposed to take a month to get the part from O'Reilly. Nope. A month later they can't get the part, and they tell me that they might be able to get it if I wait another 4 months. So, I gave up and told the dealership to order their $790 dollar part. Three days later (yesterday) they get the part and try to install it. Tech calls me up, "The part that came in is Canadian, and I can't install a Canadian cluster into your Dodge." I assume it was due to KMH instead of MPH. Anyway, I've had it at this point, so I told the guy I just wanted my truck back, and that I will never be back. Guy ordered (or coincidentally received) the wrong PCM AND the wrong cluster. He seems entirely incompetent. After 3 months and almost $1000 nothing has changed on my truck, the cruise light is still on (always) and doesn't work! In case you're wondering, the cluster does not throw any codes when tested. I wish I wasn't so dense in this area. Can the cluster really be the issue? Can I get one from a junkyard? Should I keep trying to find a new one somewhere, or can someone just fix the one that I have? Should I put pressure on the dealership to get back some of the money I squandered with them? Thanks for all of the advice!

I THINK they are a M10x1.5. if not, they are probably a coarse thread M8. If you have an ace hardware or home depot anywhere near, take one of the nuts and head to the metric aisle. From there you should be able to figure out what it is.