Interesting observation for those CTD owners

I drive an '04 3500 Dually that has 9974 miles on the clock. It also is equipped with a full Banks kit and triple gauges on the A Pillar. Last week , while driving using heavy throttle and the engine pulling hard, there was a severe engine stutter. This was not a miss fire, it was like no power at all for maybe 1 revolution. I lifted my foot. No error codes. Engine completely recovered and the truck drove as normal. I tried the same thing again, no problem. On Saturday, using heavy throttle again I saw the fuel pressure gauge drop from its normal 6 PSI to 2 PSI and I lifted my foot and the pressure immediately returned to 6 PSI. Sunday I changed the fuel filter and all is normal again. The observation is this. Had I not had the fuel pressure gauge installed, I could have easily trashed the high pressure common rail pump by allowing it to cavitate. There apparently is no low fuel pressure detection with this truck. Undoubtedly, this is the cause of so many pump failures we all hear about. So BEWARE. We all know periodic replacement of fuel filters is not sufficient to avoid this problem. It only takes one bad tank of fuel to clog the filter. I highly recommend the installation of this gauge and a spare filter under the seat. Mine just paid for itself in spades. Steve

Reply to
Steve Lusardi
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Well, yes, but no. The 2nd gen trucks, '98.5 to '02, with the VP44 pump are very sensitive to lack of fuel. The CP3 pump on the common-rail trucks is much more tolerant of low fuel pressure, and failure of these pumps have been very few and far between, compared to the VP44 failures.

However - you just found out how barely adequate the stock fuel pump is for these engines. When adding power upgrades that deliver more fuel, you really need to do something about the fuel system to keep the CP3 fed with fuel. I would highly suggest one of the available pusher pump kits for your truck. A normal running pressure of 6psi doesn't leave a lot of room for error. To compare, I run a FASS system on my truck, which idles at 17psi, and at WOT with about 600HP, won't drop below about 12psi.

Reply to
Tom Lawrence

Tom, I have considered a FASS, but I have no experience myself with one. Since you now run one, you must have done some homework on which one delivers the most bang for the buck. I have been playing with the simple idea of using a commercial pump a strainer and a fine particulate large capacity filter. I believe I can find these as new old ex military stock locally as an alternative solution. I think half the problem is line size. It really is too small. Please enlighten me with your experiece. I don't particlarly want to reinvent the wheel. Steve

Reply to
Steve Lusardi

Without question, the stock lines/banjos are pretty restrictive. Most pusher pump kits come with replacement lines and AN fittings, replacing the stock (5/16"?) lines and banjo bolts. Originally, I went with a kit from Diesel Dynamics, which removed the stock lift pump and replaced it with a Carter pump mounted on the frame rail. Larger lines were used, and the banjos eliminated. This worked fine for a while, but the pump was very noisy, and I was noticing a gradual decrease in fuel pressure delivered to the injection pump.

I liked the FASS for it's larger filters, easier to change (they're the spin-on variety), easier-to-access water drain, the availability of a 3 micron filter (the ones available for the stock filter canister are 10 micron), and easier to service should the need arise. It's very easy to adjust the delivered pressure up or down, by simply removing a plug and changing a spring (the manufacturer has various springs available). Of course, it's ability to remove air from the fuel is it's big claim to fame, and is more beneficial on a 1st of 2nd gen truck, as any air in the fuel acts to retard injection timing (since the injectors are fired by hydraulic pressure).

The one downside to the FASS, that I don't like, is you can no longer fuel the truck while it's running. The reason is the FASS draws a LOT of fuel from the tank, and returns most of it. The return line gets plumbed into the filler neck vent. Because of this, putting fuel in through the filler neck creates positive pressure in the vent, which will spit the fuel that the FASS is returning out of the filler neck.

The solution to this is simple... install another return directly into the tank, and use that for the FASS return, leaving the filler vent free. Once I get the proper motivation, that's what I'm going to do (drain/drop tank, drill new hole, mount fitting, clean out plastic shavings, re-install).

Hope that helps out some...

Reply to
Tom Lawrence

Thanks Tom, You may have your work cut out for you adding another port to that tank. Mechanical fasteners of any variety will not hold in plastic. The only way to make this work is to have an internal metal plate for the flange fasteners to clamp against. If you are lucky, there may be enough available real estate in the factory port flange. Thanks for the advise. I believe you are correct and I have no other choice except make this mod. I'll start gathering bits and pieces now. On pump noise, all pumps are noisy. I will try to use rubber isolation on the mount. Steve

Reply to
Steve Lusardi

The company that makes the FASS does exactly this for their '05 kits. Since the '05 trucks have a factory in-tank pump, they have you install a new suction tube in the tank. The bulkhead fitting has a backing nut and gaskets, etc. You can see it in their installation instructions:

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I can't hear the FASS unless I'm outside the truck standing next to it. With the Carter pump, even with it's rubber isolators in the mounting bracket, I could hear it over an idling engine inside the cab.

Reply to
Tom Lawrence

Tom, what transmission do you have in it? How about if ya have the time, post a list of the mods thus far. I'm starting to get nibbled by the bomb bug again.

Roy

Reply to
Roy

I'm running an ATS Stage V trans:

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- Initial installation
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- Minor repair List of mods? Let's see if I can get these in order:

Gauges - pyro, trans temp, fuel pressure Air box - Scotty Ram Air III Turbo Air Guide

4" exhaust w/ Aeroturbine DD pusher pump kit DD Jammer turbo, ATS manifold, DD air box ATS Stage V tranny Edge EZ TST PowerMax - at this point, dyno'd at 490RWHP Upgrade fuel pump to FASS system Banks High Ram intake - mainly because it looked cool :) Upgrade to twin turbos -
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boost, oil, and water gaugesRe-flash TST to twins programATS Billet flex plate I think that about covers it (I assume you don't care about all the non-power-adding crap :)
Reply to
Tom Lawrence

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