Well I haven't checked pressure yet. I'm trying to find a diesel fuel gauge and the Parker access valves to screw into the top of the fuel filter housing to check pressure. The truck revs up and down at idle, blows white smoke, had a sLightly dead pedal and had very little power. No check engine light is on. New fuel filter

sounds like your timing slipped ..... need to verify timing first .....

It started up and ran fine for 30 seconds then all these problems started.

as for the dead pedal, that runs off a cable, not electronics. :humm:

Running two set-ups parallel sounds nice!

Now I'm trying to understand more of the concept so I can soon set this up. So if I keep the factory set-up in place with the mechanical lift pump; and then run another set-up lets say with an electronic lift pump, with it's own fuel lines and pick up tube, that would be joined together with a "Y" connector at the P7100 factory fuel inlet. Having a valve near that "Y" connector on both the fuel lines going into the pump in case one of the lift pump set-ups had a failure, I can run one or the other without fuel being pushed back through the fuel lines of the failed set-up?

Function wise; during daily driving I would have the electric pump off with the valve closed and have the engine run only off the mechanical, and when I do need some extra fuel I can open the valve and have both lift pumps feeding the pumping? Would the fuel flow into the pump be decreased with two different fuel pressures from both pumps joining in the "Y" connector throwing the path of fuel off? Would it be possible to do the visa-versa set-up and run the electric all the time, and have a fuel dump for the mechanical pump and only use that pump if the electric fails?

no one spends a lot of time at 4K ha ha!
if he did lift pumps would be the last worry; more like picking engine parts outta his a^& "ahem" teeth...

Factory lift pump has been good to me for hundreds of thousands of miles. as long as i have 25 psi at idle im not too worried about psi under load.
btw: hello all i'm new here

I'm new here also. Well I guess I'll put on a new lift pump and hopefully fixes it. I'll let you know.

I'm not sure if it's what he's talking about or if it will even work with these pumps, but the only time I've ever seen dual pumps where one was a "backup" in case of failure, they were sequential. That was a 350 Chevy with a pusher in the tank, and the backup was a puller under the hood. If the tank (stock) pump failed while he was out in the woods, he could flip a switch and limp home with the one under the hood. It was all the same fuel lines though, he was just powering the spare through a switch instead of wiring it properly he didn't want it on all the time with the other one.

I never heard of anYone running two pumps. It would be a lot of messing around for somEthing you would probably never use. BUt if you're out and you break down then it would be nice to have

the concept is easy ..... one large fuel feed line from tank ( if your wanting high HP get a sump and plumb it on the bottom of the tank ) .... run a Y @ lift pump or before and plumb it to the lift pump and the other to the electric pump .... post electric pump I would put a 1 way check valve so fuel can flow out but not back through the electric pump .....

then wire the electric pump up on a realy with the activator ( signal voltage ) comming from a low pressure switch ( like 20 psi or so ) and have it also turn on a small light in the cab to let you know its on as well ..... incase your LP fails completely ....

make sence now ? :hellox: