latitud_rt

I am sure this has been covered, but I was thinking about installing a Carter 4601 as a pusher in series with the factory lift pump. My question is - what if the pusher goes out? Would the pressure drop to zero? Has anyone plumbed some sort of bypass in case this happens? My factory pressure is down to 5 at WOT, cruise is at 9 tp 10, idle 12 to 13.
I would love to get a RASP or FASS II, but the cost is too much at the moment. The Carter is $90 and plumbing and wiring should be no problem mounting it back at the tank.

Any ideas or suggestion?

ratsun

Thats the exact set up I did prior to going with the FASS when I installed the twins. It worked great for over a year with my week LP 6psi@WOT I only changed it thinking I was pushing the envelope with the factory stock lines and my mods. The Carter pusher with the factory LP gave me a solid 17-18psi

Gear Poet

Ya, if the pusher pump goes out, the pressure drops to between 2 and 8 psi, depending on which way the pusher's impellers are turned when they stop.

I have a Holley Red inline with my stock LP. I plumbed a bypass using Y-connectors and a simple ball-valve. The Red itself has an incab on/off switch.

Ya, I'd have to reach under the truck to turn the lever if the Red ever died. But... simple and cheap, right?

latitud_rt

When you ran the wiring to the pusher, did you run it off of a relay and then trigger the relay from the factory harness? Sounds pretty simple. I assume a in-line ball valve cutoff could be picked up at Homed Depot or the likes.

ratsun

Yes on the relay

latitud_rt

Well this morning I saw pressure of 3.8 to 4.0 so I am going to have to do something immediately. So I ordered a new lift pump, 3990105, from a local shop. The cost was $162. I am going to call the dealership and complain since I had the truck in for surging under load and they said they drove it and didn't notice any problems. I asked if they noticed the fuel pressure and they said 5 was ok. I asked them to do the flow test and they said there was no need....
I tried to explain with a 9,000 lb camper, the pressures were low. Oh well, better safe than sorry. I will keep my current pump for a spare. I am still planning on adding the carter as a pusher when I get downtime.