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Need Help No Fp

956 Views 28 Replies 6 Participants Last post by  muggs
Hey guy's,
Here is the situation: my FP guage has never dropped below 16psi...today while driving I noticed it at 14 than 10 min later 12...I thought well no big deal. I stopped to fillup with fuel ( low fuel light just came on...filled up drove away and within 3 min my fuel pressure dropped to 0..shut truck down cycled pump to see if it was filling up..heard it filling filters climbed under truck broke filter loose bumped truck and filter is filling up..still 0 on my FP guage..what do i need to do...could I have air in the system?? Thanks for your help:confused013:
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Faulty gauge? Thats also a possibility.
 

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Discussion Starter · #3 ·
Brand new 1 week old...boost and pyro guages working fine
 

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Have you checked your fuel filter? Mine did something very similar to what you describe. It turns out it was clogged and barely flowing just enough fuel to run...but no more.
 

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Discussion Starter · #5 ·
No, will do now... seems to be ok still no FP on guage but seems to run fine does this make sense? do you think that my injection pump may have taken a s&#$?
 

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May as well check the inexpensive stuff first. I've seen people spend big bucks on a repair, only to find out that something simple/cheap was actually the culprit. :doh:
 

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Discussion Starter · #7 ·
Oh ya..I agree just don't know where to go from here..broke filter loose again and it pours out when I bump the motor..checked lines no kinks etc. Scared to drive don't really have the $ for injection pump..anybody else have any suggestions??
 

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Discussion Starter · #8 ·
Bump...anybody else have any ideas...thanks
 

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I have heard from several members about faulty isspro fp gauges.
 

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Discussion Starter · #10 ·
Really...how woould I check for this?
 

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Im not sure, might call whoever you got the gauges from and see if they will swap it for a new one. Or buy a new gauge and send the bad one back.
 

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Discussion Starter · #12 ·
k...I'll see what they say Mon morning. you think it will be ok to drive FASS seems to be working fine. Also how long would the truck run before I get the imfamous dead pedal if the FASS was not working..
 

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Im not sure how long it will run. I think some run several thousand miles before you know its dead without a fp gauge.
 

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You should check it with a second gague, mechanical test gauge, or cheapo electric. It's not worth the risk not knowing.
 

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Discussion Starter · #15 ·
Where would I check the FP at the FASS or at the isolator block under the hood?
 

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There is a test port on the IP. Shrader valve. With a test gauge you could at least see your idle pressure. If you have a FASS on there your pressure it probably good, but it's just a pricy risk not knowing.
 

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Discussion Starter · #17 ·
I agree I believe the FASS is operating correctly. But I will check my isolator to see the FASS is putting out...as stated earlier the FASS has never went below 16psi even with a load...and it's hard to believe that it checked out...more than likely and hopefully the gauge took a dump..which is also aggervating when you pay good money for a FP gauge and it doesn't operate correctly. I will be taking it back Mon morning and have them order me another guage at there expense it's only 1 week old...Thanks for your help
 

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What exactly do you mean by "broke filter loose"? Just because there's fuel coming out doesn't mean there's good pressure.
 

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Discussion Starter · #19 ·
I climbed under truck and loosened the fuel filter to see if there was fuel..should I check this at the isloator for the guage I mounted under the hood ( coming from FASS system fuel line running to isolator and plastic tubing exits the isolator and goes to the FP guage. I would think that if I have fuel making it to the isolator than it's a faulty gauge would that be correct? new to the diesel world learning as i go...Thanks for your help..
 

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I would ditch the isolator and get a needle valve.
 
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