stock in tank lift pump?

[cumminapart]

my truck shouldn't have had an in tank fuel pump hey?what im asking is what me as second owner putting in the raptor 150 and finding stock in the tank could mean..1. vp44 has been starved?2.was there any special order in '01 that would make this possible stock3.he replaced with another stock lp in the tank (wasn't there a recall?)

[flagmanruss]

There wasn't a recall. If there was a fuel pump failure, the dealer fix (the only one possible as dealers no longer had acess to the on-engine pumps) was to retrofit the intank pumps. Too bad DC did not go for an aftermarket style remote pump. The VP44 may or may not have been replaced, depending on whether it failed too. Can you access the dealer records?

[AH64ID]

The in-tank is a good unit, but still falls short of the optimal psi for the VP44, on the HPCR trucks is great. Really every VP truck should have a fuel psi gauge, so I would start with that and go from there.

[cumminapart]

well i drove the truck for about a year before i put in the raptor 150.... but because of shipping the edge came sooner and my pressure was reading a steady 10 with the in tank pump once replacing (which turned into a nightmare not realizing my problem was that my raptor was trying to pull through the in tank pump) i can hold my pressure up above 14psiim curious now because the first and only owner before me claimed to have complete records but once i actually went to buy the truck i didnt really worry about it....maybe i can still get themactually i shall try.. lol .. but since he sold it about 2 yrs ago he may have gotten rid of them.. i might at least look up the vin # because if all his service records were under warranty they should be under any vin records

[bcbigfoot]

My truck had the intank pump and a remanufactured VP44 when I bought it with 105,000 miles. I checked the fuel pressure of the in tank pump before replacing it, it had 7psi at idle and wide open throttle was 2psi. My experience is that the intank pump is not much better than the factory engine mounted lift pump.

[cumminapart]

before i put in the raptor i was holding 10psi at idle... if i remember correctly i was only seeing it drop to about 5 at most with wot

[Mopar1973Man]

before i put in the raptor i was holding 10psi at idle... if i remember correctly i was only seeing it drop to about 5 at most with wot

OUCH... That just too low...

Keep it in the green...

[cumminapart]

yea quite low but still just a little better than the stock lp pressure bigfoot was seeingmy raptor holds its up there at 18 now and i have the edge set to beep at me when it sees 10.. haven't heard it yet.. it'll usually drop down to 14 and i've seen 12 at the lowest

[Mopar1973Man]

Hmmm... You still have a restriction some where... Typical fuel pressure drop on a 150 GPH pump should be only 2-3 PSI tops. Just for food for thought my old Carter stock pump new use to drop 4-5 PSI on stock plumbing. Then switch over to the Vulcan Big like Kit and stock Carter and only had 2-3 PSI drop... Then upgrade to a AirDog 150 now only 1-2 PSI drop. But seeing a 8 PSI drop from Idle to WOT there is something wrong...

[cumminapart]

i haven't done a whole lot of testing yet but.... it may have had something to do with my torn connector tube oringi was talking to you today about it while i was doing the injector swap ended up having to drive 45 minutes to cummins this afternoon for 6 orings.... but i think it may have fixed my hard start issue alsoanyways... truck started up pretty easily. had my buddy watching the lines and tightening as he saw fuel didnt have one tightened hardly and it completely came back off on my test drive so it made a mess then but after that i havent seen any leaks so farmy fuel pressure is seeming alot more steady now but i'll check tomorrow how much of a drop i can getwould a connector tube o ring effect pressure drop much?or would it be because i dont have the big line kit between the filter and vp

[Mopar1973Man]

i haven't done a whole lot of testing yet but.... it may have had something to do with my torn connector tube oring

i was talking to you today about it while i was doing the injector swap

ended up having to drive 45 minutes to cummins this afternoon for 6 orings.... but i think it may have fixed my hard start issue also

anyways... truck started up pretty easily. had my buddy watching the lines and tightening as he saw fuel didnt have one tightened hardly and it completely came back off on my test drive so it made a mess then but after that i havent seen any leaks so far

my fuel pressure is seeming alot more steady now but i'll check tomorrow how much of a drop i can get

would a connector tube o ring effect pressure drop much?

or would it be because i dont have the big line kit between the filter and vp

Any line retriction will come and bite you... Because the smallest orfice (banjo bolts) dictate the max volume it will supply at the VP44...

Best way to show this example of restrictions is lets say you house is on fire. You know your garden hose has 80 PSI of pressure but the garden hose is only 5/8" ID hose. Your wife calls 911 and gets the fire department coming in the meantime you keep fighting the fire with your little 5/8" garden hose and losing the battle. The fire department shows up and pulls a 2 1/2" hose off the truck and charges it at 80 PSI and now winning the battle. Your fire is put out! What is so different? No matter what the size of the fuel line will dictate how much volume can be pushed through the fuel line. Like the story above the water pressure was the same at 80 PSI but the hose size jumped from 5/8" to 2 1/2" ID hose and the volume changes is size of hose. So the same thing applies to the stock fuel system. The stock banjo bolts and 6mm ID pipes are just too restrictive and cannot supply enough volume of fuel for that VP44 demands. This why I highly suggest you go up to 1/2" ID plumbing.

[cumminapart]

i've still got some fuel line hanging around maybe i'll see if i can throw something together or i'll just buy one of the kits but i could probably do it cheaper myself