Another fuel pump question

[jonathan1950]

So for the past few weeks my fuel pressure has dropped from 19 psi at idle and 17 psi cruising, down to 16 psi at idle and 14 psi cruising.  I have checked all my hoses and they look good, put a clamp on one hose that may have had an issue.  If I park the truck facing down hill it will start after a week of setting no problem, but if the truck sits level or facing up hill then it takes a long time cranking to start.  If I bump the starter and let the fuel pump cycle then it will usually start quickly.  I have notice that as the tank gets lower it seems that the fuel pressure drops one or two psi.  Other than starting over with a new fuel pump and big line kit, I am not sure.  I have read about Raptor pumps going bad, so not sure if this is the issue or not.  Another thing I have noticed is once in a while when I bump the starter the fuel pump does not come on?  I replaced the relay under the hood, but it still seems to be just an occasional thing.  Wondering if there could be an electrical issue instead of a fuel issue?

[mopartechnician]

Leave the fuel cap loose and see if it has hard starts. The fuel pump doesnt always run when bumping the starter. The ecm decides if it wants to or not. Also i have been wiring the signal wire into the window motor fuse and it has fixed weird hard starts. You can also pull the relay and put power down the red wire of the relay harnesd to power the pump to see if it works. Might also need a ground. If the fuel pump doesnt run, call pureflow with your serial number and they will send out a new one no questions asked

[Yankneck696]

In many cases with the truck pointed downhill & curing the issue, it's the fornicating banjo washers on the back of the head. Enjoy...

Ed

[Ilikeoldfords]

I agree with Ed. That simple trick of pointing it down hill vs uphill makes me think that there is a leak in your line somewhere. Even leaks in the return lines can and will cause you issues down the road. Start by checking the banjo fitting on the back of the head and the return line tee underneath the stock fuel filter canister.

[jonathan1950]

Thanks, I will see about getting some new washers for those and changing them out.  Would that cause low fuel pressure also?  That has me a little confused, I can understand the loss of prime, but I have not heard anyone say that with a fuel leak they also have low fuel pressure.  Guess if the washers fix the hard start I will have to see what happens with the fuel pressure.  The next time I drive the truck I will leave the cap loose and see what happens.  I will keep you posted, it might take a while as I will be riding the bike more and more with the nice weather.

[Yankneck696]

THe pressure issue could be the seal on the Fornicating Rump Raping Pump going bad & leaking fuel into the motor. Check where the wires enter the grommet for diesel. If found, Call in for warranty & don't accept NO for an answer. If they give you a hard time, ask for Jason & mention my screenname & full name.

 

Ed Grafton

[jonathan1950]

Thank you for that, I hope to pressure wash the underside of the truck in the next few days, after I do I will drive it for a bit then check for leaks.  If I find any I will let you know and contact them.  Thank you again Ed for the information.

[jonathan1950]

Yank, I do not see any fuel coming out from the wires, I will keep an eye on it though.  I am wondering if it might be related to the draw straw?  It seems that when I have a full tank of fuel the pressure is near normal, but right now I am down to a quarter tank of fuel and at idle I am sitting at around 15 psi, running at 60 mph, empty I am sitting around 12 psi.  Not sure why it would drop like that as the tank was going down other than the draw straw?  I have not found any other place, but did get some washers for the return line at the back of the head, so I hope this week to get them installed.