clc900

Super. Im curious what you know about the in tank fuel pumps from a 99 F350 V10. I removed mine from the tank when I converted to the 12 valve. I know the 12V lift pump is pretty reliable but Im wondering if I could or should use the V10 pump inside the tank. Got any info??

Superduty

I dunno about the V10 pump. Are you sure it is an in tank pump ? They'd need a different pump, lines and tank for the diesel then. I'd think they would use the same parts wherever they could.

The PSD pump (Bosch) is frame mounted on the driver's side rail under the cab. If your truck has it, you are set to go.

clc900

I took the gasser pump and sending unit out of the tank and replaced it with the diesel sending unit. I dont have a in tank pump or a pump on the frame. I did have a filter on the frame rail but thats gone now. All I have now is the mechanical lift pump drawing fuel out of the tank and sending it to the mechanical injection pump. I have heard the gas and diesel tanks are diffrent (lining?) but I have been running the gasser tank with no problems so far. I did change out all the fuel lines though.

Superduty

I don't think the tanks are different, but my guess was wrong on the pump. You get what you pay for. If you have the diesel sender in then you have the diesel pickup in too. Just put a Walbro or Bosch pump on the frame rail and you are good to go.

Why did you change the fuel lines and what was different about them ?

Superduty

"So this begs the question, why wouldn't Dodge use this in their retrofit kit if it is such a good pump? Why put another POS pump in the tank if you got this one in your parts bin?"

I have no idea. The thing about using the gasser pump, ASSUMING IT WILL HANDLE DIESEL FUEL, is that there would have to be a pressure relief somewhere in the system, because that pump will obviously make 60-80 PSI without too much trouble. And there is no pressure relief in the Dodge/Cummins fuel system.

Here is the thing though. The stock diesel pumps are probably failing because there is no pressure relief.

On the 2nd gen engines, the ECM directly controls the fuel pump and it runs it at 7V during starting. It does this so that the pump isn't straining against an engine that isn't taking in any fuel.

On the 3rd gen engine, the ECM controls a relay that runs the fuel pump. When you turn the key on, it runs the fuel pump for 2 seconds. When you crank the engine, it runs it for 25 seconds. It does this so that the pump isn't straining against an engine that isn't turning over.

However, the 7V and 25 second values are just estimations. There is no fuel pressure sensor on the ECM. So if you get more viscous fuel, like in the winter, the fuel system is probably pressuring up quickly and the pump is straining against an engine that isn't taking any fuel. The motor probably stalls.

There is nothing worse for a DC motor than to stall.

Because this is still how these trucks operate today, I expect that the new in tank retro pump being installed is going to fail as well. Every time the truck is started that pump is basically running deadhead and stalled.

It would have been very easy for Dodge to fix the fuel supply systems on these trucks. Put the gasser pump in the tank and put a pressure relief on the injection pump. Done deal, no more trouble.

SBishop

SD,
You might find this interesting.

https://www.dieseltruckresource.com/...ad.php?t=88820

Superduty

I looked at it and didn't see anything special. Am I missing something ? The guy has a hopped up Duramax and he put a 100 GPH Carter on it. Umm... ??? nothing special ? I don't get it ?

Stock Duramaxes run without a fuel pump at all. He put the Carter on. 7 PSI sounds like a carburetor pump. It is probably wired to the key so it will be dead headed while the engine starts. Probably doesn't have a pressure relief. Pump will probably burn out over time. ????

The only thing is that when his Carter stops it will starve the CP3 and wreck it. Without the Carter, the CP3 would feed itself. I think the fuel filters are special on the DMax for low restriction. Guys are putting on the Cat 2 micron filters (like mine) and running into restriction problems or on the verge of them. One can only draw fuel so far/through so much restriction before you reach a limit. (14.7 PSI atmospheric pressure limit to be exact.)

Superduty

DTR User USCG has the following in his signature:

"Ryan's Holley Blue LP kit (15psi+) Dead after 6mos/5,000mi."

ctdhombre

So this guy is using a fueling setup that according to Superduty is not proper.

Wonder why it works?

Superduty

It will work for a while. They all do. For a while.

The DMax ECM doesn't turn the pump on/off while cranking. The pump probably doesn't have a pressure relief. It will be dead heading while starting. It won't last long doing that.

When it fails he'll starve the CP3.

I wonder if 7 PSI is at the pump or at the CP3 ?

User USCG has "Ryan's Holley Blue LP kit (15psi+) Dead after 6mos/5,000mi." in his signature.

All it takes is a dirty fuel filter, some cold fuel, a few too many starts, etc. and they die.

Berak

I'm still running on my stock filter mounted pump, wonder why it works? Simple, it hasn't failed YET. Dodge themeselves doesn't seem to like it much either since they change over to a tank mounted pump when it does fail.

All mechanical parts wear and fail eventually. Most of them will last for a certain amount of time even if under engineered for their job. What we want is a robust cost effective solution that gives us a reasonable expectation that our fuel system will perform for a good long time. This can only be verified with multiple users and extended use periods but the basis for the re-designed system needs to start with the facts and implement something that seems to address the most prominent shortcomings of the system that is exhibiting premature failures.

Time will tell, but Superduty's reasoning and the move to a more robust pump sure make sense to me.

SBishop

ATS is selling a reworked CP3 with the FASS fuel system for the Dmax's.
Maybe they know something about the FASS that we don't.

http://www.atsdiesel.com/ATSWebsite/...M/FuelPump.asp

Superduty

If I ever need a "duel feed" pump, I'll give them a call.

Is the "secondary high pressure feed pump" the FASS ?

"The other issue that arises from this condition is the fuels inability to lubricate the internal injector pump and injectors."

Injector lubrication too ? Not that I know of. Either the CP3 gets enough fuel to keep the fuel rail pressured up and the engine runs or it doesn't. If the rail is pressured then the injectors are "lubricated".

I'll leave it at that.

signature600

IIRC, someone said they were using the large volume and pressure of the FASS to "boost" the pressures inside the CP3. I believe they are operating inside it's "overkill" zone.

But I already have a good lift pump, so I don't pay much attenion to ATS, or many of the other "big names." They don't like us primitive guys anymore

Chris

linetrash75

Superduty, I really like this walbro pump, execpt for 1 thing the 10mm inlet and outlet. My question, is there enough meat there to drill and tap to 3/8npt or 12mm. I'm sold, its just that one thing, may not be a big deal to you but I went thru alot of trouble to enlarge my fuel line to 1/2 inch and will do everything I can to keep it that way. On a side note I will be going with that 2 micron filter on your other post but think I will remove factory filter completely, though would be nice to have fuel heater in winter. I would like your input on the resizing in and outlet.

Jed