Tractorman

I have experimented with a couple of LED headlight bulbs, but so far they aren't outperforming my halogen Sport head light setup. I was fortunate enough to get good reflectors when I purchased the Sport headlight package a few years ago. I may not get the lumen capabilities that the LED's offer, but my halogens light the roadway as they should - both low and high beams. I use GE NIGHT HAWK XENON 9007NHX lamps as recommended by Danie Stern (Daniel Stern Lighting). - John

Oops, I overlooked the high beam indicator. I am not seeing a lot of difference in distant light output when switching to high beam. Maybe your upcoming photos will show that better. - John

@dieseldon, I couldn't tell if your photos were showing low beam and high beam separately, or were they all just low beam? Maybe you could shed some light on that (ha! ha!). Thanks, - John

Interesting what you describe - I was having the same symptoms. I never considered an injector issue since the RV275 injectors were new when this started happening on my truck. One thing I didn't mention is that the miss would go away when I used cruise control, even when it was pulling hard in 6th gear climbing a long grade. That kind of threw me a curve. I wondered if the ECM altered timing when on cruise. It was the only thing that made sense at the time. So, now I am wondering if I got a new injector with low pop pressure right out of the box. Maybe I am masking the problem by setting the timing to stock....? @Alexio Auditore, you will have to let us know what fixes your engine miss. - John

You are describing something very similar that happened to me. It did turn out to be an engine miss under the same driving conditions as you are describing. Mine started just after I installed RV275 injectors. I didn't notice it immediately because I wasn't driving anywhere to utilize the power. It showed up on my first tow (only pulling a 4,000 lb trailer), mostly when accelerating in 6th gear. It felt like when a gas engine has an irregular ignition miss and, like you say, I couldn't hear it but I could feel it under a load in the higher gears. For awhile I even thought it could be mechanical. This haunted me for about 18,000 miles. I use a Smarty S03 tuner and I even set it back to stock. The miss disappeared, but so did the engine torque. To me the test was inconclusive. I lived with it and tried various things - I even replaced the transmission mount - all to no avail. Last December I was getting tired of hearing the timing rattle (enhanced by winter blend fuel where I now live) so I set the timing back to stock and left the rest of the tune alone. Timing rattle gone and no engine miss! Under any condition! I left the timing set at stock, even through the summer. Periodically, I advance the timing just for a test and sure enough the miss returns. Running stock timing has had no adverse effect on performance or fuel economy. May not be your issue, but then again..., - John

Your first post is dated Wednesday, but I never saw this post. Your post today showed up right away. Maybe others are having the same issue. I am sure you will be getting responses soon. This is a good site for your kind of questions - it is a good source for 24 valve second generation trucks in general. My truck is an '02 with the NV5600 and a stock clutch. I have the RV275 hp injectors and a Smarty S03. I don't tow as heavy as you, but the truck runs well and has been reliable. EGT's are always below 1200 degrees. Most of my driving is between 1500 - 2200 rpm. On a rare occasion I have been up to 2500 rpm. - John

It would be interesting to see a photo of that fuse after that event occurred. What you have described is indicative of a poor electrical connection at a precise location, the fuse stud. It would also explain why the nearby fuse didn't break the circuit. Here is a possible scenario: Truck electrical system is consuming 60 amps. Poor connection at stud causes a 6 volt voltage drop at at the connection while alternator is flowing 60 amps (less than 1/2 alternator capacity) through the circuit. If a voltage drop test would be performed during the event, one might see 18 volts on the alternator side of the connection and 12 volts on the battery side of the connection. This would be a voltage drop of 6 volts while flowing 60 amps. In your case both numbers easily could have been higher. 60 amps x 6 volts = 360 watts of power at a very precise poor connection easily equals a glowing stud. Kind of like the glowing tip of a 300 watt soldering gun when not contacting any work. A very similar experience happened to my brother-in-law a few years ago. He had Les Schwab install a battery isolator and a new auxiliary battery in the engine compartment of his truck. The setup was for his slide-in truck camper. We all went camping - us in our camper, them in theirs. After several days of camping at one site, we left for to go elsewhere. At our first stop along the way, my brother-in-law says that he was sold a bad battery because it blew up just after he left the campground. We raised the hood to take a look. Sure enough part of the top and side of the battery was missing. But what wasn't missing was evidence. The battery cable eye that was still clamped with a wing nut to the positive battery post was severely discolored by heat along with burned and melted cable insulation in the immediate vicinity. Not a bad battery, but a glowing connection that ignited the hydrogen gases from a rapidly charging battery that was discharged at the previous campground. One good reason not to use wing nuts for battery connections. The point is that everything was working as it should, but a poor connection created a serious problem and a safety hazard. For all of the above reasons I do not rely on the physical appearance of electrical connections with high amperage circuits. One needs to know if the electrical continuity is good at a given connection. The only way to know that for sure is to perform a voltage drop test while the circuit is under a load. @Mopar1973Manprovides an excellent article in how to perform this test. - John

@JAG1, you are describing a camper very similar to what I used to own. Mine was a four season Citation with basement made by General Coach in Canada. The manufacturer stated that the camper weighed 2700 lbs with 20 gallons of water and two full propane tanks. With our gear thrown in, it weighed about 3,500 lbs. Combined with the truck - about 11,000 lbs - 4,850 on the front and 6,150 on the rear. As suggested by others, you should weigh the rig. Weigh each axle separately and write the weights down. You will probably find that your front axle weight will increase only about 500 lbs or less. The rest of the weight will be resting on the rear axle. I used the Rancho 9000 series shock absorber because there are 9 adjustable positions to incrementally control resistance to the hydraulic flow when the shock extends. This makes the shock perform well with a loaded or empty truck, especially a loaded truck with a high center of gravity. Let us know what the results are if you decide to weigh the rig. - John

Good suggestions and and questions that need to be answered from @AH64ID. One more question to add. Is your camper an all season camper with a basement? If so, this raises the center of gravity considerably. - John

That is a great solution! I considered doing something like that when I had my slide-in camper. I should have done it, but I never followed through. I sold that camper about six years ago and bought a 19 foot travel trailer with a single slide. My GCW is now 12,000 lb (only 1,000 lb more than with slide-in camper) and I now have four braking axles and a low center of gravity - much more relaxing to tow. - John

Am I missing something here? My truck empty: Front axle - 4,400 lb. Rear axle - 3,050 lb (air bags at 5 psi or less), 9000 series rancho shocks - rear on 3, front on 5 Gross weight - 7,450 lb My truck with slide-in camper: Front axle - 4,850 Rear axle - 6,150 (50 psi in air bags) 9000 series rancho shocks - rear on 8, front on 5 or 6 Gross weight - 11,000 lb With slide-in camper and 50 psi in the airbags, the truck handled well. If I recall, the rear part of the overload spring made contact and the front part had a small gap. Heavier bumps engaged the overloads. - John

Sounds like a faulty bridge to me. That was an attempt at humor. Actually, it seems that your solution was a good one. - John

Just curious - did you find an obvious cause for the death wobble when you inspected and replaced those items? Or, was it more that they just looked like they needed replacement, so you replaced them? Just wondering because for many the death wobble has been hard to figure out. @Doubletrouble, be sure to let us know what you figure out. So far I have been fortunate and have never experienced the death wobble and I know that I am not exempt from it occurring to me. - John

Death wobble can be hard to diagnose because there can be many causes and because the right conditions must be present to make it occur. Some things that I would be looking at.... Do you have oversize tires and wheels? Heavy rotating masses can enhance the triggering of death wobble. Has the truck been lifted? Are tires worn evenly? Every steering linkage joint and every suspension linkage joint should be inspected for looseness including shock absorber mounts and shock absorber condition. Sometimes minor play or wear on multiple components can trigger the event. - John

I didn't know the overflow valve was made both ways. It would be an interesting test to see if the results were different. - John

I believe the small hole is for venting air such as after a fuel filter change when using the bump start feature. I also believe that when the engine is running at any rpm and if lift pump pressure is below 14 psi that the overflow valve is still in full operation because the lift pump feeds directly into the inlet of the positive displacement internal vane pump. The flow out of the vane pump is regulated at a much higher pressure and is in common with the 14 psi overflow valve as well as other components inside the VP44. It is my belief that as soon as the engine starts, the 14 psi overflow valve is in operation. - John

Let us know what you find.... don't leave us hangin'! - John

It seems to me that there are three possible things to try.... 1. Replace the overflow valve - usually I don't recommend parts changing, but sometimes when diagnostic tools are not available, changing an inexpensive is a good solution. 2. Test the overflow following Mike's procedure. 3. Install a temporary mechanical gauge and strap it to the windshield wiper arm and test drive for a day or two. This should confirm whether or not you regular gauge is giving you reliable data. Typically, the overflow valve is fairly bullet proof. - John

I think the article is informative and factual based on limited information available regarding the VP44 fuel injection pump operation. Appreciate you taking the time to provide this information.

Just want to make sure - are you performing each voltage check while the grid heaters are cycled on? This would be the proper procedure. Also, are you using the same ground point for each test? - John

My wife and I just moved into our newly built house just 10 miles northwest of Baker City. From @Mopar1973Man' place, it is 86 miles (compass heading 251 degrees) as the crow flies - much farther if you use the highway. Friday, November 13th - first round 8 inches Sunday, November 15th. - second round 7 inches Sunrise - yesterday morning - John

@jlwelding, are you considering the swap for your 2001 truck in your signature (doesn't show transmission)? If so, I would definitely consider the swap, especially since the truck weighs in at 10,000 lbs. NV4500 - input torque 460 lb/ft, dry weight 195 lb. NV5600 - input torque 550 lb/ft, dry weight 360 lb. Compare gear ratios. First gear and the two top gears are virtually the same for both transmissions. However, the NV5600 offers one more gear where you need it, making it a close ratio transmission. You will feel the difference in performance., especially getting a load moving from a stop on an upgrade. I am approaching 350,000 miles on my truck and I have had no problems with the transmission. Of course, I am no where near @Mopar1973Man's 500 hp, but my truck has been known to break traction on a snowpack. - John

I could see that why that setup would be and absolute "must" for a marine application - water all around and high dew points all of the time. Although, on the upside should a breakdown occur, there is usually plenty of parking, but on the downside, most places the anchor won't reach the ground. - John

This is not a case in which you are right or wrong. Over the years there have been many posts on this site (and other diesel sites as well) that have portrayed a strong belief in that if the lift pump does not maintain over 14 psi at all times, then fuel return flow from the VP44 is greatly diminished, thus causing damage to the VP44. I do not believe that this is the case at all, and here is why: The lift pump flow feeds directly into the suction side of the internal vane pump (inside the VP44 injection pump). Since this vane pump is a positive displacement pump, engine rpm determines the input flow and the output flow of this vane pump. The lift pump can and does provide a positive charge to the vane pump inlet, but the lift pump cannot push more flow through a positive displacement pump than the positive displacement pump is flowing, hence the pressure rise on the fuel gauge. The fuel flowing out of the internal vane pump is subject to a much higher pressure relief valve setting (I've read somewhere between 120 -200 psi, @Mopar1973Manmentions 60 psi). It is a good portion of this flow from the internal vane pump that makes its way over the 14 psi overflow valve and returns to the fuel tank. @wil440, thank you for your timely post. Your test supports what I am trying to portray. - John

Personally, I would not be concerned about the pressure drop generated by adding another filter in the circuit. If you add the filter, the pressure drop will be the same across the added filter regardless of the lift pump's location. I think a frame mounted lift pump will be more efficient and you would always have a positive pressure supply to the added filters - that also equates to less chance of drawing in air. By the way, five years ago I removed my in-tank lift pump and installed a used FASS lift pump on the frame rail - not added filters, just relocated the lift pump. I believe a lot of folks are putting way too much emphasis on a specific fuel pressure gauge reading. Having a pressure gauge at the inlet of the VP44 injection pump will tell you that there is specific pressure at a specific time, but it does not say anything about a specific flow. However, it does tell you that the lift pump must be be trying to flow more than the VP44 is accepting at any time, otherwise the pressure would not be there., I say this because there are some very important unknown pieces of information regarding the vane pump inside the VP44 injection pump. For example: What is the internal vane pump's displacement (in gallons / hour) at a specific engine rpm? What pressure is the internal vane pump's relief valve set? Just knowing this information would go a long way to gaining a better understanding of how this fuel system works. - John