After many moons of procrastinating, I finally got my IssPro 30 PSI mechanical fuel pressure gauge rigged on the 2003 HO. Install was reasonably easy. Just popped out the fuel supply banjo on the fuel injection pump, and threw in a tapped banjo with an elbow, a stainless line and away we went.<br><br>First impression is that the noise is considerably higher than a direct connection to a VP44. I may try snubbing it down, but I think I'll move the tapped bolt back to the filter canister next weekend and see how it affects noise and pressures.<br><br>And the fuel pressures:<br>Idle - 9 - 9.5 PSI<br>Cruise at 60 mph - 8 PSI<br>WOT - 5 PSI<br><br>Rod

 

Well, I can't complain about my 2001.

 

Yeah, don't complain about your 2001. ;D It appears as though the new lift pumps aren't even as durable as the old ones, at least from the BOMBing perspective. TST has pretty much killed their lift pump in a couple months of testing.<br><br>In the new year, I'm going to work on a swap kit, but I need to know some tech specs on the Bosch pump.<br><br>Rod

 

What does the lift pump actually do? is it just a transfer pump pulling fuel from the tank to the injector pump? Is it mechanical or electric?<br><br>Dan<br>Sorry dont have my diesel yet and new to diesels...

 

On the 24 valve trucks, the lift pump is an electric fuel transfer pump. It pulls fuel from the fuel tank and then lifts through the fuel filter canister and up to the injection pump.<br><br>On the 12 valve trucks, the fuel transfer pump was a mechanical pump.<br><br>Rod

 

PushRod, Page 14-60 of 2003 Service Manual, Fuel Delivery, &quot;Transfer (Lift) Pump Pressure, Minimum 9.5 psi. I would say your's is borderline. ???

 

[quote author=Sierra Phil link=board=20;threadid=8410;start=0#84880 date=1040883544]<br>PushRod, Page 14-60 of 2003 Service Manual, Fuel Delivery, &quot;Transfer (Lift) Pump Pressure, Minimum 9.5 psi. I would say your's is borderline. ???<br>[/quote]<br><br>We're in a state of confusion about that particular spec. Where do you test for that minimum 9.5? In the section about the lift pump, it tells us that its an 11.5 PSI pump. So I'm assuming (we both know what that implies) that the 9.5 minimum would be right at the lift pump outlet. Since I was testing down on the injection pump, its not unreasonable to see a 2 PSI drop across the fuel filter and that little wee fuel line. So I think my current lift pump is good and when it hits 7.5 PSI at idle, its done for. But again, these are assumptions and if I ever find anyone who knows what they're talking about at Dodge, then I'll post some proper guidelines.<br><br>Rod

 

from reading alot of posts is seems to me that the lift pump is common modification why not just use a good quality aftermarket pump and be done with it. you can get a higher pressure pumps and just put a regulator in line. Or spec one that will do the job.<br><br>Dan

 

[quote author=df5152 link=board=20;threadid=8410;start=0#84953 date=1040918488]<br>from reading alot of posts is seems to me that the lift pump is common modification why not just use a good quality aftermarket pump and be done with it. you can get a higher pressure pumps and just put a regulator in line. Or spec one that will do the job.<br>[/quote]<br><br>The problem with the 03s is that the lift pump now mounts to the fuel filter canister, and uses an O-ring to seal the pump to the canister. So to switch to an aftermarket pump, we'll need to come up with a hose fitting that has a 4 bolt mounting plate and O-ring. Then we'll need to find a spot for the aftermarket lift pump. <br><br>And we also want to get some numbers from the stockers. Longevity, pressure, etc etc before we go wild with replacements. Everything is in the theory stage right now as far as pressures and longevity goes.<br><br>Rod

 

why does pressure matter? It would seem to me that what you realy need is volume. Especially if its just a tranfer pump. Do u have a picture My truck has not arrived yet...

Dan

 

[quote author=df5152 link=board=20;threadid=8410;start=0#84957 date=1040919245]<br>why does pressure matter? It would seem to me that what you realy need is volume.[/quote]<br><br>&lt;chuckle&gt; You're bringing up an age old arguement :-) Pressure is a function of volume in a system such as this. So if you see your pressure dropping, the only way its dropping is because you don't have enough volume to maintain it. On the old VP44 pumps, there really hasn't been an agreement as to how much volume is necessary, and on the new pumps, no-one knows either. <br><br>I'm thinking about springing for a flow meter and doing some testing, but its kind of hit the back burner for awhile...<br><br>Rod

 

US the age old method get a big glass jar and time how long it take to fill the jar. dont spend amoney a a flow meter save it for the new pump....<br><br>Dan