53 willys

I was going to ask what temp the return fuel is after going through the CP3??? is it really that hot??
anybody know??

ptgarcia

I'd rather use the cup and add a cooler inline.

PEAKSTRYDE

I agree, which brings up a good point WhY don't these trucks come with a return fuel cooler??????

I wonder if anyone has installed one like on a GM right before it goes back into the tank?????????????????????????????????????????



MARK,

Its HOT, I could barely touch my buddies return fuel cooler on his DSNAX after we got back from a cruise around town in "HOT" mode.



I will try to get some temps this weekend and post them. I would say the return fuel temps are upwards of 90* + and if you think about hauling a trailer for a few hundred miles and everything is loaded and "working" I wouldn't be suprised to see quite a bit over 100*.


Then factor in the temp increase of the whole tank............... It's warm

ptgarcia

The GMs don't use a lift pump, correct? That would mean all fuel is flowing through the CP3, correct? If that's the case it's possible the DMAX return fuel is hotter than the Cummins. Am I missing something here?

gmctd

The "brown corrugated tubes" are actually the spring-loaded tubing sliders which provide tension on the reservoir\cup to keep it firmly located in-position on the bottom of the fuel tank - they allow a 'one-size-fits-all' module

The basic Dodge\Jeep module is 14" fully extended, 10" fully compressed - the Dodge gets a pump, the Jeep doesn't.

Might be possible to drill the module top cover to take advantage of those tubes for additional fuel supply\return capabilities - the tubes are part of the cover, and slide into corresponding holes in the plastic bracket clipped around the lower 'cup
That would allow use of the original Dodge module to retain use of the in-tank lift pump for emergency bypass.

Whadday'all think?

BTW - has anyone looked at the '03-'04 Dodge tank modules? They have the filter-mounted Carter pump, so no in-tank pump

CP3 bypass-return fuel would be at maximum of engine coolant temperature, as the inj pump is bolted to the timing cover immediately behind the radiator - a fuel-return line cooler is designed-in on the Dmax CP3 systems - might not be a bad idea, here, particularly if you're installing a hi-output pump\filter-system for hi-power performance increases - 'specially, one with a small electric fan, like the DeRaile systems

Hope this all works out for ya - the direct-replacement '06 Dodge\Cummins lift pump module is working most excellently in our Jeep CRD, which, like the DMax, had no auxiliary lift pump - talk about yer aeration\cavitation\bubbles causing slight engine fishbiting\misfire\hesitation, sometimes long-starting events - that was all caused by the fuel manager assy being mounted higher even than the engine head - all symptoms eliminated, gone, now.

PEAKSTRYDE

PAULY,

You are correct! Yes it is possible that the DSNAX return fuel is slightly hotter but the heat comes from compressing the fluid?

Not be much heat is created in the CP3 just because it is drawing from the fuel tank!!!


We installed a LP on my buddies GM right infront of the tank on the frame rail and the temp of the return fuel cooler is not noticibly any cooler.


I like the idea of a fuel cooler simply because you can really never have your return fuel cooled enough. Cool fuel is a positive thing!!

ptgarcia

On the DMAX system, the return has to be on the pressurized side of the injection pump, no?

On the Cummins system, there is a return on the low pressure side, between the transfer pump and injection pump, correct? Is there also a return on the pressurized side of the injection pump?

I guess what I'm getting at is the high pressures of the injection pump with heat the fuel to higher temps than the low pressure of the transfer pump.

cquestad

On Dodge Common Rails...

There is a return line off of the CP3...

There is a return line off the rail (assuming the RV opens)...

And if you have a "non deadheaded after market lift pump"...you will also have return fuel there.

Fuel is really moving all over the place with these trucks...

ptgarcia

Thanks, that clears up some of the confusion in my head.

Sixpack73

the setup with the in-tank lift pump requires that the lift pump be running in order to open the flapper valve on the bottom of the cup and let fuel in. obviously not a great way to do it if you are bypassing the stock LP in favor of an aftermarket pump.

on the jeep setup, it uses the flow coming from the return line to open the flapper valve.

Sixpack73

you do realize that the majority of your return fuel has never made it to the engine compartment, right? its mostly coming off the bypass valve from your aftermarket pump. I doubt it would be hot or even warm at that point. You could always keep a separate line for the return fuel coming from the cp3.

edit: I spoke too soon. I see the thread viewers already arrived at this conclusion

but just for cquestad, the point is just to have the fuel returning into the cup (or basket as some call it) to help avoid the sloshing problem at below 1/4 tank. its probably not needed for everyone though.

treadway47025

What do you mean when refering to the dead headed aftermarket lp?

Sixpack73

Update: well the '05/'06 Jeep Liberty CRD fuel pick-up assembly got installed today. It was a good fit for my '06 Ram and nothing "special" had to be done to install it. Just removed the old assembly (that has the pump in it) and put this one back in its place. The fuel gauge works fine too and didn't appear to be off at all. No electrical splicing for the sender was needed either. It uses the same plug.

Unfortunately it was 38 degrees today with dense fog and a slight drizzle, so I didn't bother taking any pics. I couldn't feel my hands and I ended up covered in diesel I almost passed on the swap today, but I really wanted to get it swapped out before the snow blows in tomorrow and all next week. I didn't have anything else productive planned for the day so I went out and braved the weather. oh well. its over now

Anyway, initial impressions are very positive! At exactly 1/4 tank it worked flawlessly and showed no signs of foam or bubbles in the lines. Pressure was a steady 34 psi (apparently I need to back off the check valve a little). Took it for a short spin and flogged it once or twice and it dropped to 20psi and stayed steady there until I let off it, and it went straight back to 34. I'm running the beta 4.4 smarty and it does use a bit of fuel so this is normal. Never had a problem with fuel sloshing at any stoplights/stopsigns either.

After I have a chance to drive it some more next week I will post up any additional feedback I find. But again, so far so good! [keeps fingers crossed]

.

53 willys

that's good news!!!
the more I think about it the more I want to just ditch the in-tank set-up and just set myself up with a way to attach a pump(holly or Carter) on the frame rail for an emergency use....I think with one extra set of fittings it could be done....fast too...
keep running it low on fuel and let us know how it does!!!
thanks

gmctd

Well, congrats, then - I was hoping it would work as well for y'all as the Dodge lift pump module works in the hereto-fore pumpless Jeep - I think it is a good exchange of technology, this for that, tit for tat, satisfyingly rewarding.