Upgrading in-tank LP ?s
 

After driving a bit, I decided that I want more fuel going into the injection pump, after a hefty replacement. I am looking into the Raptor 100 and which way would you go about tapping into the tank, any way around dropping the tank? The pain is that I just topped off and don't want to drive around with insufficient fuel pressure and hate to transfer it.

as far as i know the lift pump gets installed inline with the fuel supply line. on mine the line runs along the frame under the cab on the driver side. to prevent the fuel from siphoning out when cutting the line i blew air down the line to clear it of fuel first. then i ran the pump while i bled the air out.

How much pressure are you getting to the pump... As long as its above 7psi just wait till you run that tank empty. There really is no other way. You do NOT want to put the raptor in line with your stock in tank pump still connected. If you are going the drop the tank though i would get a sump style pickup. I had my draw straw run me out of fuel when i wasnt completely empty.

And there is another solution ....
Install the new pump on the rail ....wire it up - and keep power to the in-tank lift pump.

The in-tank lift pump will feed the new rail mounted pump ...plenty of pressure ....
When the tank is nearly empty - finish off the project ....drop tank and modify.

Alternately - leave tank full - lift the truck bed up/off the chassis and do your work from above. Plenty of people say taking the bed off /putting back on is less work/easier to do that dropping and re-installing the fuel tank.

Take the previous stated suggestion, if you're fuel pressure is fine then run the tank down, I've actually seen a sump that doesn't require dropping the tank, you cut the hole in
The bottom of the tank and feed their "horse shoe" up thru the hole. With a little finness you can save yourself over an hours worth of work, and no 1/4 tank issues. May run into 1/8 or lower tank issues under hard acceleration/braking.


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The challenge is I'm running 8.5 psi at idle and drawing down to 6-7 under moderate throttle. Would the raptor help volume and pressure if i put it in series to get through this tank or does the pump in the tank completely restrict flow even running? Just installed this IP and don't want to roll the dice, not a gambler. The truck has only 48,000 miles and on it's 3rd vp44 (counting the original), this thing is chewing them up like m&ms.

Do you have a block or in-tank lift pump currently? If you need to access the tank, I suggest lifting the box off. I have dropped the tank, and pulled the box, and pulling the box is easier for me. Also, the tank can be full to the top when pulling the box and it won't make a difference.

In regards to running the pumps in series for a little while, I do not recommend this. I did this when I was out of town one, and the truck has never fueled the same since. I had a failing LP in the tank, then bought a block mounted pump. At idle I had 31 PSI of fuel at the VP44!!!! Way too much. At WOT it dropped to 16PSI, a definite flow issue.

If you have an intank pump, here is what I suggest. Buy the Raptor100, and pull the box off and install one of these:
DrawStraw™ V HiFlow

It will remove the pump assembly from the fuel basket, I have done this myself. I have never had any issue with low fuel level and still having fuel pressure.

If you have a block mounted pump, install the Raptor100 and put a bypass block in where the block mounted pump was.(this is what the factory did to mine, less the Raptor)

I was thinking about the Raptor for my dodge, but i have a 2000 with the out of tank pump. I was wundering if it was worth the extra money to just get a FASS or Air dog or do these smaller, no filter, Raptors do just as well?

I think the extra filtration is well worth the money.

I'm thinking of utilizing the new pump to drain the tank into a drum, drop the tank, modify the pickup, install tank, install the new pump and use the old pump to put fuel back in. I don't have an a-frame or adequate help to lift it off. The only issue is where to pull the fuel out of the tank? As I understand, the return line has a check valve as well as the fill tube, maybe I can pull it past the LP in the tank?

I've dropped a tank half full. By myself. with a jack to act as a 2nd person, jack stands and some dunnage you'll be fine. I used my raptor to empty the tank from 1/4 when I did my sump and it took a while. Just run it as low as you can and then drop it, once you remove tank, remove sending unit and you can siphon it out- modify unit with draw straw or whatever your plan is and put tank back empty. it's pretty simple.

A valid point ....but if you can ensure the pressure reaching the Injector Pump has a maximum of 20 PSI at IDLE, and doesn't drop below 10 PSI at WOT ...it will work quite nicely. (I did this on one of my trucks when it wasn't convenient to do the in-tank mods ....and I deferred the in-tank work for many months ....BUT - I did monitor the pressure at the input of the IP to ensure it never was outside allowables. I also fed the power to the rail mounted pump via a oil pressure switch; the engine had to be running, oil pressure > 5 psi to get power to the rail pump.

Ok, here is the chain of events. 1. Put hose on the fitting out, 3/8 is perfect. 2. Used in tank pump to pump fuel into a clean and new 32 gallon garbage can in the bed, bypassed the relay to avoid bumping the starter a 100 times. 3. Dropped tank and modified basket. 4. installed tank, which getting the retaining ring back on was fun. 5. Syphon fuel back into the tank from the garbage can.

I now know what killed my vp, the lift pump started taking a dump after it got to a 1/4 tank. It was only pumping in spurts, don't know if it were a low fuel issue or the pump cannot sustain long runs. For the first 40 minutes it was solid but the last 20 were telling of why the fuel pressure was fluctuating.

Tomorrow, finish install of the raptor, new filter and going to get a Racor in the next few days.

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All done and have 15 at idle and draws down to 12 at WOT. I haven't hot the highway yet but will be on the road tomorrow. I have to say the pure flow AD folks were good and called right back yesterday when I wanted to make sure I had the pick up tube in right. Nice to have my truck back. Thanks everyone for your input.

Glad it went smooth, hopefully it's the last of the fuel system issues.

I hope so too. I just hope to get at least 100,000 miles off my rebuilt IP.