I just installed a Raptor 100 pump today. When i finished i attempted to bleed the lines. I bumped the ignition over the pump started and after i adjusted it i ended up getting 18-19 psi but when i start the truck my gauge reads 0. I wanna believe there is some air at the sensor but i cant figure out why it only works when the truck is not running. Any help will be appreciated. I really need to get this thing runnin. Also is there anything special to do make sure i get all the air out? Thanks

 

How is yours set up? On mine I have a bypass valve that lets fuel go back to the tank at 16 lbs. this valve hangs up a lot. If your set up has a return line like mine, clamp it shut with a pair of vise grips or something and see if your preasure returns. Air should not be your problem, the guage does not care if it measures fuel or air preasure. My pump will still pump 16 lbs with or without fuel.
I took out the vp44 leaning this. Just a thought.

 

All i did was disconnect the factory supply line
(left it right there on the frame) and ran the new 1/2 line. i didnt mess with a valve.

 

So if I understand correctly you are going from the fuel tank to the new lift pump and from the lift pump directly to the fuel filter then on to the vp44.
The truck will run with 0 lbs, I would hook up another gauge to eliminate the gauge being bad. If you don't have a gauge, a cheapy from autozone, ect. will work. If it still reads 0 then make sure you have power and ground to the fuel pump when the truck is running. If you have power and ground at the fuel pump and 0 lbs check for kinks in the new line. Make sure you use a volt meter to check the connections. Check the battery voltage and you should have battery voltage at the pump. You can light a test light with very little voltage. If all of this is ok then you can assume the pump is bad. You can remove the pump and run it is a bucket to test it off the truck. USE EXTREME CAUTION IF YOU CHOOSE TO TEST THE PUMP IN A BUCKET. JUMPER WIRES AND FUEL IN A BUCKET CAN MAKE A BIG FIRE! I STRONGLY DISCOURAGE THIS PRACTICE FOR THE RISK OF HARM AND FIRE! If you have any questions give a yell. I hope this helps

 

Yeah that is how i have it set up. Thanks for the advice i have a friend coming over with a gauge hopefully tomorrow.

 

Good luck, let me know how it works out.

 

Where is the bypass valve? do i just clamp the return line off?

 

on my truck it is between the glacier pump and the oem filter. It came in the kit and looks like a tee. One line goes from the pump to this tee, another goes from the tee to the filter, and the third goes back to the fuel filler neck. At 16lbs the tee lets fuel bypass back to the fuel tank. MY valve has failed and I have clamped the return line with a pair of vice grips to get me home. It is also a good way to diagnose the pump or the valve as bad.
It sounds to me like your system is not like that. Do you have a return line anywhere in this system that you had to install when you put in the pump?
You could also block the factory return line, but be careful where and how you do this. Plastic line does not like being clamped. Blocking the factory pump would eliminate the regulator in the vp44. I don't think that is your problem though. Try a different gauge first and see if you have pressure. If you do not then get a 1/2 inch tee and put the guage back by the pump and clamp the line going to the engine and see if you have pressure. Do you still have pressure when you bump the starter?

 

No the system i got only included a supply line i haven't touched the return line yet.
Yeah i get plenty of pressure when i just bump the starter thats why i cant figure out whats goin on. The gauge shows i am getting bout 18 psi when i just bump it but when i start the truck the gauge just sits at 0.
I can rev the truck up past 2500 rpms and it sounds, acts, and feels normal. I moved it once so to get it outta the way till i get it fixed and when i was moving the gauge showed i was getting fuel pressure but soon dropped right to 0. I am still waiting on my friend to bring his mechanical gauge but i may just have to go buy one.

 

Unless someone else pops in here with a different idea, I am still leaning towards the gauge. It has to be the next step in the diagnostic approach. If it still reads 18 when you bump it and 0 when it runs then I am thinking pressure regulator. Leave the manual gauge on and somehow block the return line. If the pressure stays up it is the regulator. I have read about the regulator being removable but I have never done it. Another thought would be crap in the tank getting sucked up in the in-tank screen/filter. A clogged filter can be checked by pulling a fuel line at the filter and run it into a 2 liter bottle. It needs to fill the bottle at least half full in 25 seconds, if it does the screen is fine and the volume is ok. We are now back to the regulator. Splice a piece of hose in the return line so you can clamp it shut. Pressure = bad regulator. If you have any questions pm me and I will give you my tel # to call. It might help to call.
Otherwise good luck and let me know how it turns out.

 

I guess i will try to pick up a gauge today and try your advice. Is the regulator in the VP? if so does that mean i will need a new VP or can i replace just the regulator?

 

As far as I have read it is in the vp but it can be removed.
I would have to do some research on it because I have never changed one.
I would have to find out if it is in the vp and removable, this site should take care of that. Then find out if you can buy one. I have a dealer that my wife works at that is very good with dodge parts, otherwise maybe someone online here might have a bad vp with one in it that they are willing to part with.

 

Well today i started it up moved it bout 50 feet and then outta no where the gauge starts working and continued to work so i took it for a drive and it has worked fine. But i was driving and then the gauge dropped to 0 but i was almost home so i continued on and then the gauge came back on. So i am thinking its a gauge problem now.

 

I think you may be right. Change the gauge and see. These will run with 0 lbs pressure as long as they have fuel to suck. When they do not have fuel the vp44 takes a hike and fast.

 

just checked the codes off my truck got a P1682, P0216. So i guess my VP is bout to die