Engine/Transmission (1998.5 - 2002) New intank pump as a pusher pump

[MBFARMS]

Just an update. We put a new LP in the factory location on my friend's truck and put an intank pump in the tank. All lines are factory and fitting are factory. We wired the pumps with two separate relays, the pumps getting the power from the battery. Started the truck up and it pegged the 15 PSI gauge in the truck. Got a mechanical gauge and attached it to the schrader. 22 PSI at idle. We were both amazed. The throttle response was better and there has been no hard starts so far. Time will tell on this setup. He is ordering a new 30 PSI gauge so I will have more info later.

 

[nps]

Sounds like there is hope for the intank pump after all.



I think that a Carter 4600 wouldn't peg the 15psi gauge - its a 8 PSI pump. Along with the intank pump I suspect it would keep pressure right around 15-16, where the LP is at alone (when it works)

 

[Tcolesanti]

Just a note, I installed a FASS II pump in line after the intank pump on an '02, fuel pressure is about 23psi, goes to 20 at WOT. I think it is a great setup, just don't know what will happen when the intank pump takes a crap. Guess I could disconnect it and see what happens.

 

[Huff N Puff]

Good thing you didn't listening to all those nay sayers,glad you proved it for yourself. Thankyou for the good infomation.

 

[DDouglas]

Well I have had the in tank set up for about 5 months and was not happy with the pressure, a high of 9 psi and at WOT it would suck down to 3 psi. Not enough pressure. so I talked to a diesel mech. and he said put another lift pump back where the old one went an run it with a relay , and on the banjo fittings I drilled the two holes closest to the threads , open them up to about 1/4 inch and cleaned up all the holes with a small file then washed them to make sure no small loose pieces of metal where left from the drill bit. and put it all back together ,and wow i have 23 psi and at WOT it drops to 20psi. I did this about 3 weeks ago and so far it has been great with no problems, I unhooked the intank pump to see if it was to fail if the regular lift pump would still pull fuel and it did, but only 14 psi and 10 psi WOT. but that is better than the intank by itself. so with both of them it works great. if anthing changes I will post on it.

 

[Silver_Ram]

I am interested in the in-tank pump & the stock lift pump combo.



But my friends at G&R Diesel installed that setup yesterday on a truck & ended up with 30 PSI, which is supposed to be too much. They talked to a local VP44 rebuilder & were told no more than 25 PSI or it would rupture a diaphragm in the VP44. Maybe a combination of bigger lines & bigger fittings will help.



Guess we'll have to see what happens when MBFARMS friend gets a 30 PSI gauge.

 

[MBFARMS]

My friend has Stewart Warner gauges and they only make a 15 PSI and 100 PSI. The marks are too close on the 100 so he is stuck with the 15 PSI guage. Things that he has noticed so far, improved throttle response and the tach is rock solid when idling. The engine seems a little quieter too.

 

[nps]

I am interested in the in-tank pump & the stock lift pump combo.



But my friends at G&R Diesel installed that setup yesterday on a truck & ended up with 30 PSI, which is supposed to be too much. They talked to a local VP44 rebuilder & were told no more than 25 PSI or it would rupture a diaphragm in the VP44. Maybe a combination of bigger lines & bigger fittings will help.



Guess we'll have to see what happens when MBFARMS friend gets a 30 PSI gauge.

Use a Carter 4600 pump instead of the stock LP (equivalent to the 4601). It'll take your pressures down.

 

[MBFARMS]

Just to add a follow up to this thread. I have the Vulcan big line kit with the LP back by the tank running from a relay. The other day the Lp started cavitating and dropping pressure. So I decided to put the intank pump in as a pusher. Parts were under warrenty so they were free. System is installed and I am seeing 25 PSI at idle and 22-23 PSI at WOT. Truck seems to have a little better pickup. System has been installed for three weeks now with no problems.

 

[jeepit]

Just to add a follow up to this thread. I have the Vulcan big line kit with the LP back by the tank running from a relay. The other day the Lp started cavitating and dropping pressure. So I decided to put the intank pump in as a pusher. Parts were under warrenty so they were free. System is installed and I am seeing 25 PSI at idle and 22-23 PSI at WOT. Truck seems to have a little better pickup. System has been installed for three weeks now with no problems.

Are you saying you are running intank and an LP or just intank?

 

[nps]

Are you saying you are running intank and an LP or just intank?

He's running the intank pump as a pusher, so both are installed.

 

[MBFARMS]

Yes both are installed. I have a Vulcan big line kit that is installed with the factory LP by the tank and the intank pump in the tank as a pusher.