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  #41  
Old 07-26-2011, 04:40 AM
busymountain busymountain is offline
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Smile Raptor a problem?

I am wondering at what pressure the overflow valve opens sending fuel back to the tank? We may have covered this already somewhere but I could not remember if we had.

I am thinking they set the pump at around 40psi or so. Would high pressure cause any permanent problems with the p7100? It seems like I read somewhere that if the pressure was to high it could blow out seals? Am I remembering that correct?

I don't have a fuel pressure gage so I am going to take this down to a local shop and have them check the pressure.
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  #42  
Old 07-26-2011, 05:40 AM
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From what I have read, 45psi is the max you should see, though mine runs right at 45 so that's not an issue either. 50psi is where things supposedly start to blow out, though I read a week ago that this is a better pressure, still not sure on that. Stick with max of 45 for now. The overflow should open at 45 or so, that way the pressure is always at 45, though this is highly reliant on the lift pump (though having a raptor you should always be at 45) since engine RPM pumps it more, you will only see 20psi at idle.

With your issue, I don't see it being the problem. I don't see how it could pop open properly sometimes and then just stay open the whole time letting all the fuel pressure flow through it.
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  #43  
Old 07-26-2011, 06:22 AM
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I wonder if the valve spring is a little weak and once it pops open it stays open. Sounds goofy, but maybe...... Try either replacing the valve or pulling the spring and measure the height of it. I should be 1/2" long. It can be stretched but that is a temporary repair. If you look around on the internet you can find them fairly reasonably priced.
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  #44  
Old 07-26-2011, 09:21 AM
busymountain busymountain is offline
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Default pump overflow valve

Quote:
Originally Posted by MnTom View Post
I wonder if the valve spring is a little weak and once it pops open it stays open. Sounds goofy, but maybe...... Try either replacing the valve or pulling the spring and measure the height of it. I should be 1/2" long. It can be stretched but that is a temporary repair. If you look around on the internet you can find them fairly reasonably priced.

Its pretty tough to get mine out. I wish the truck was here to send a picture. The valve cannot be removed without losening the p7100 from the engine. The shop just replaced it and had a terrible time with it, scarred up the block side trying to make room to remove before losening the pump to get it out.
It must have something to do with mixing the 94 with the 93 parts.

So I take you think the spring may be to short or lose allowing fuel to bypass to easily? What do you think about not enough pressure to the P7100? Enough to idle but not quite sufficient for power.
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  #45  
Old 07-26-2011, 09:33 AM
busymountain busymountain is offline
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Quote:
Originally Posted by ISX View Post
From what I have read, 45psi is the max you should see, though mine runs right at 45 so that's not an issue either. 50psi is where things supposedly start to blow out, though I read a week ago that this is a better pressure, still not sure on that. Stick with max of 45 for now. The overflow should open at 45 or so, that way the pressure is always at 45, though this is highly reliant on the lift pump (though having a raptor you should always be at 45) since engine RPM pumps it more, you will only see 20psi at idle.
With your issue, I don't see it being the problem. I don't see how it could pop open properly sometimes and then just stay open the whole time letting all the fuel pressure flow through it.

ISX thank you for looking in on this.

Are these raptors somehow controlled by the engine rpm? I thought it was just a pump with 1 speed 1 pressure? I am trying to make sure I understand this correctly.

I was thinking that the overflow may be open constantly from to much raptor pressure. The truck would seem to run fine except when you put the boot to it, then it would kind of slug out because the fuel is getting diverted back to the tank. Maybe the raptor is set to high or the new valve spring is bad, either case the fuel is diverted away from the P7100.?

Have you ever heard of these raptors not running at high enough pressure? If they set the pressure in the shop at what seemed good around 30psi at about 2000 rpm they may not notice a problem. When it gets under a load however it might be a different story. You said these things should be set around 45psi.

I have not heard back from the shop as to what the pressures where when they installed it yet. I want to make sure they did it correctly. They have a new tech who installed the pump but he is a factory ford tech so, I am not sure if he was directed to make the pump work right.

Last edited by busymountain; 07-26-2011 at 10:34 AM.
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  #46  
Old 07-26-2011, 10:37 AM
busymountain busymountain is offline
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Quote:
Originally Posted by busymountain View Post
Its pretty tough to get mine out. I wish the truck was here to send a picture. The valve cannot be removed without losening the p7100 from the engine. The shop just replaced it and had a terrible time with it, scarred up the block side trying to make room to remove before losening the pump to get it out.
It must have something to do with mixing the 94 with the 93 parts.

So I take you think the spring may be to short or weak allowing fuel to bypass to easily? What do you think about not enough pressure to the P7100? Enough to idle but not quite sufficient for power.
..
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  #47  
Old 07-26-2011, 12:16 PM
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If it was just replaced then I would think the valve is fine. Far as mixing the parts, there should be no difference and on some of the blocks grinding a relief for the overflow valve is required. You need to put a fuel pressure gauge on it so you can see for yourself wht is going on with it.
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  #48  
Old 07-26-2011, 01:20 PM
busymountain busymountain is offline
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That will be our next attempt to find the problem. We already know we have to drill out the middle of the bango nut to add our fuel pressure line. Hopefully we can get it done soon - thanks
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  #49  
Old 07-26-2011, 01:25 PM
busymountain busymountain is offline
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Red face

Quote:
Originally Posted by MnTom View Post
If it was just replaced then I would think the valve is fine. Far as mixing the parts, there should be no difference and on some of the blocks grinding a relief for the overflow valve is required. You need to put a fuel pressure gauge on it so you can see for yourself wht is going on with it.


Have you heard anything about too much pressure from the supply pumps causing any of the problems we have been looking at?
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  #50  
Old 07-26-2011, 03:44 PM
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Instead of drilling out the Banjo bolt, you might try and use one of THESE.
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