I have a 98.5 24v that is just turning 94k and I was wondering what preventative measures I should take to avoid LiftPump and VP44 failure. I’ve heard that most go out at 100k if they are going to. And based on parts running 1300-1800.00 I’m getting worried. Should I be running some kind of extra lube in the fuel, due to the fact that the VP44 doesn’t lubricate when the truck is idling and not moving. I assume that means the VP44 is not lubricating as I sit in traffic jams with the engine running, or am I wrong on that one and it’s nothing to worry about? Also it sounds like the LP will fail due to fuel demand and that causes the VP44 to take a dive. Is it best to put a pump like the Holley Blue inline to help the stock LP? Is this unit just a simple toggle switch type inline fuel pump and will that keep the VP44 from going out by aiding the pull on the stock LP?

Next what about a fuel PSI gauge, and where do you run it in. I assume I’d need to tap the in banjo bolt going into the VP44 and run it from that. Or does that give a reading relative to the actual draw from the VP44 and not the true PSI pulled by the stock LP or LP/Holley Blue setup?

Sorry for all the questions but 1.5 to 2k in parts is something I just can afford.

Thanks

 

You can get a guage pod that goes on the a pillar right in front of you, you can get a single, double, or full triple pod, looks pretty cool, for sure get a fuel press. gauge, and I recommed EGT and trans temp, to hook the gauge up you do not need to tap the banjo bolt, on your 98, there should be two plugs on top of your fuel filter canister, 1 before filter and 1 after filter, I run my gauge after the filter, ( also get a new fuel filter if you havent). if you cant afford the gauges right now, just get a basic fuel press. guage and test it just to make sure your LP is good. If your LP is good, you should be good right now being stock, its when you get the high HP you will need a relocation kit or FASS

 

the496rocket

when running the gauge to the after (assume outlet test port) will I be getting PSI levels lower than direct from the LP. The Haynes put the stock 99 24v at 5-7 cranking and 10psi running at idle. Those numbers are off the inlet test port (first cap on filter top). I think the 98.5 is closer to the 99 in design so the top psi caps should work like you said. Overall 5-7 and 10psi sounds low to me and if running off the outlet test port after the filter I should see psi lower than that. I thought a stocker would run in the 12-14 psi range.

Thanks for the input and I'll start looking for gauges.

ed

 

This is similiar to how mine is hooked up. This configuration is not complicated and gives you a good reading. Mine ran about 12 at idle, 10 on the road and 7 or so at WOT. The first lp lasted about 120K and the second about 40K. My FASS holds a steady 19/18/16 day in and day out.

 

my 98.5 currently is 14.5psi pre-filter and 13.5psi post filter. stock power level and LP location.

 

those pressures are a bit low, usually 14-15 psi idle, get your fuel pressure checked to see what you are running in the meantime if you cant get a gauge right away. you wont see much pressure drop if any from the inlet or outlet port, unless the fuel filter is really plugged, I just like to run mine there so I can monitor my fuel filter along with the LP.

 

Guys, Thanks for the input and I like the idea of using the outlet port and being able to judge filter from PSI. The photo of the gate valve type setup looks good and I'm going to get to the parts house this weekend and see what I can find.

 

The threads in the filter head are -2 NPT (1/8th inch national pipe thread) you can use an NPT to JIC adapter or NPT to hose barb your preference.

To accurately "judge" the filter health you need to read the pressure differential. the pressure difference between the inlet and outlet. What I found out from a chrysler tech buddy is about 1.5psi pressure differential the filter is done. you need a differential guage and plumb it correctly to both ports in the filter head.


but for a straight pressure guage the post-filter port is going to be your best information as to what the IP is seeing.

 

I used a surplus 35psi, water pressure gauge by Autometer Industrial (made in USA) which only cost $10:

http://www.surpluscenter.com/item.as...atname=engines

Then add the tubing, adapters, and needle valve, and you should be around $25 total. This is a quality gauge and works like a top!

 

Gen 2's biggest issue is Lift pumps, which, when they go, often take the VP44 after some time.
The fix:
1. Fuel pressure gauge ASAP- Do a search on gauges, lots of reading, good info. Keep FP above 6-7. If it fall below that, replace LP.
2. Plan ahead. Cummins has a campaign pump LP for $65. Do a search for the part #. Keep it in your truck as a spare.
3. Optional: Vulcan big line kit- much larger fuel line, elininates ALL bamjo bolts. Provides nice outlet to hook up FP gauge. A lot of people also like the FASS 2 vs Cummins LP.
4. Many on the site routinely run a fuel additive which helps mileage and adds lubricity for LP/VP44/Injectors. Most run Power Service Silver(White for below 32), Lucas, 2 stroke oil from Walmart, various others.
5. Check codes by switching the ignition On/off/on/off- Then it will read out 2 sets of codes, which many here will tell you what they mean.
Theer are many opions on the VP44. I think most feel that if the fuel pressure stays where it needs to be, the VP44 is fairly reliable.
Good Luck with your Rig!

 

Good info on the PSI differential guage and test. I've seen the testers at Geno's for sale. On the surplus 35psi and worries about failure and fuel leaks from the glass, I'd assume not with rated to 35psi and max of Lp looks to be 15psi based on above replys. Also do you need to run the needle valve or that just makes dealing with everything eaiser? Also do you have any idea about the length of tubing? Geno's sells a 1/8 male/female line but only in 30". Sounds short but that would be a clean connection from head plate to gauge. May be best to run the needle in the longrun to allow cutting fuel to gauge. Good info for sure on the 1/8 JIC and NPT connections.

Thanks

 

NAPA sells a nice copper tubing line kit for abot $10, about 6' or 7'. The tubing gauge is narrow enough that I did not use a needle valve, works without flutuation.
FYI

 

If your running cooper tubing did you run compression joins just like running waterline fittings? Did you flair the ends with a flair tool or just compression joint?

Others, if I go the rubber fuel line route will any do with diesel and as for tie to the hose barbs, I assume small hose clams. If so any leaks overtime. Leaks in the cab would be bad.

Overall sounds like most of you all are running mechanical units, do they work better than electronic with sending units? Looks like the cost of mechanical is better, with that 35psi unit it looks really good.

 

The copper line is already flared, with appropriate nut on each end. It was recommeded to use plumbers tape vs teflon, as diesel will eat teflon. I certainly feel better with the copper.
Most run Mechanical, no isolator. I have DiProcol, about $40.
Good luck with the job!.

 

OK, here's everything I know about fuel pressure gauges:

1) I used the surplus 35psi water pressure (60psi on my 12-valve) AMI gauge because they were recommended by Infidel (considered by some the guru of the 12-valve forum), they were cheap at only $10, they were Autometer, and they were made in the USA. The 35psi is sufficient for a 24-valve, even with a pusher pump you'll be OK. I don't care that it says "Water Press." I used a label maker to make a "FUEL" label for it. These are surplus (with some cosmetic defect) industrial gauges, not cheap stuff. You can also use oil, boost, or air pressure gauges.

2) I did not use an isolator because they are expensive and apparently are not very reliable, I think Diesel deteriorates the diaphragm. The chances of having a fuel leak in the cab does exist, but is very remote. My gauge is down under the dash, if it leaks I'll just get fuel on the floor mats. Diesel is not as flammable as gas, if your fuel gauge should leak your truck will not spontaneously burst into flames.

3) I used 1/8 copper tubing, because I don't like the plastic tubing, it kinks too easily, although most people like it fine. You don't need to flare the tubing, just use the ferule that comes with the kit, you will also get a 1/8 inch tube to 1/8 npt pipe adapters in the kit. Don't over tighten the nut, just snug then 1/2 to a turn more, if it does leak, just tighten a bit more. If you ever take the fitting off, use a new ferule when you reassemble it. Here is a link for a coper tubing kit, NAPA has a similar one, you get the tubing, the fittings, and the ferules, you get everything that you need to use the 35psi water pressure gauge.

http://store.summitracing.com/partde...0&autoview=sku


4) Don't use teflon tape on the NPT pipe fittings, it doesn't work with diesel. Use Permatex 2. Don't use any sealant on the nut that clamps down the ferule, it is a compression seal.

5) On a 24-valve, if you use the 1/8 coper tubing, you don't need a needle valve. The fluctuations are dissipated by the small tubing size. However, using a needle valve is still a good idea because you can shut off the fuel to the gauge if you should have a leak somewhere. If you do use a needle valve to dampen the fluctuations, just open it barely enough to get a reading on the gauge. I mean barley open it, just like a small tap.

6) Copper tubing should not be used to connect directly to the engine. The engine vibrations may cause the rigid copper tubing to crack and burst. I used a flexible rubber line from Geno's garage and ran it from the injection pump fitting to the 1/8 copper tube, then ran the tube to the gauge inside the cab. Here is the line with the proper fittings:

http://www.genosgarage.com/prodinfo.asp?number=LAHF4