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7 minutes ago, Shainer said:

Hmmm...  Did FASS switch over to mostly quick connect fittings?  You keep the factory fuel basket in the tank?  My bet is your issue is on the suction side of the lift pump.  The longer it runs the more aerated it makes the fuel.  I when it starts acting up the lift pump is probably getting noisy as well but you may not be able to hear it.  You could jumper the lift pump relay harness after the engine starts missing so you can listen to the pump with the engine off.  The alternative is to disconnect inspect, clean, replace any quick connects on the suction side.  Guys sometimes don't get the one on the tank seated, or while seating it get debris in it that allow air to enter.

Yes the fuel basket is stock! Now that you mention it my lift pump is rather loud and it sounds just like air going thru it. It’s not a smooth sound it’s rather choppy. 

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19 minutes ago, Shainer said:

Hmmm...  Did FASS switch over to mostly quick connect fittings?

No, his fass has all pushloc or JIC fittings, and one hose clamp connection.  Only quick connect is where the fass connects to the stock suction supply on the basket.

Edited by trreed
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If it sounds choppy while running it's sucking air.  It does take care of air separation, but it is still possible for air to get past the filter, or there could be a suction leak beyond the pump, like in the JIC fitting above the return line.  Double check all of your connections.

I've found that quick connect fittings (particularly the style you're using) push on a lot farther than they appear before the click happens that indicates it's fully seated.

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3 minutes ago, trreed said:

If it sounds choppy while running it's sucking air.  It does take care of air separation, but it is still possible for air to get past the filter, or there could be a suction leak beyond the pump, like in the JIC fitting above the return line.  Double check all of your connections.

I've found that quick connect fittings (particularly the style you're using) push on a lot farther than they appear before the click happens that indicates it's fully seated.

I’ll def look every thing over. I remember when installing the pick up line push fittings it was a struggle to get them on and I thought they finnaly went on but I’m prob wrong. 

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I think we found the issue.  Pump is no miracle worker and can only deal with so much air before being overcome and sending it to the IP.  Air is being pulled in at the tank fitting, separated at the FASS, sent back via the filler tube, just to be aerated even more on the next suction cycle.  Wouldn't take long to whip 35 gallons of diesel into a latte Starbucks would be jelly about.

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21 minutes ago, Shainer said:

I think we found the issue.  Pump is no miracle worker and can only deal with so much air before being overcome and sending it to the IP.  Air is being pulled in at the tank fitting, separated at the FASS, sent back via the filler tube, just to be aerated even more on the next suction cycle.  Wouldn't take long to whip 35 gallons of diesel into a latte Starbucks would be jelly about.

Let’s hope this is the fix!:thumbup2:

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37 minutes ago, trreed said:

That won’t work in this instance. @Royal Squire has a 1/2” draw straw. You have a 3/8” suction port and 1/2” line. 

Would I benefit from getting a 1/2 to 3/8 reducer and short hose section? 

http://www.vulcanperformance.com/mobile/Product.aspx?ProductCode=PLC68 

Right here is what I’m talkin about. Then just grab a short length of 3/8 hose and shove it on with a hose clamp.

 

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For now i would clean up the connection and make sure you seat it good to see if that's the problem. I know those quick disconnects have a bad rep but mine have been in use for 6 plus years and they are still working fine. 

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Alright guys back to square one. Jacked up the bed removed pump and hoses and disconnected and reconnected pick up line quick connector... (It clicked into place) Loosened and retightened hose clamps on return and filler neck. Unhooked supply and return on pump and added plumbing tape. Truck is still doing the same thing. It will ONLY do this after truck has been warmed and ran for a little. in this case I ran the truck 3.5 to 4 miles. I did as @Shainer said and when it was doing it I killed the truck and bumped the starter. All I got was a bzt bzt sound and no 30 second buzz. Now I'm thinking maybe the Fass isn't working well? I am stumped now... 

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29 minutes ago, trreed said:

Can you post a video of the fass sound? Upload it to youtube first.

You wont be able to hear it over on my phone video I don't think but ill try... 

Here you go @trreed it is not doing what it did earlier so i cant video that exact sound. 

Thinking about throwing another Airtex  on to see if it fixes anything but also as a backup pump.... I dont wanna throw spendy parts at it though especially if its the VP44 going bad? The fact that it only happens when the truck has been warmed up well makes me think something besides air in fuel. If there was air getting in wouldn't it be all the time and not at a certain time? 

Edited by Marcus2000monster
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You pumping #2 diesel or 2# rocks through there?  That sounds terrible, and a lot like physical interferences in the pump.  What size fuse is on there?  Ever blow one?  Please tell me you installed the relay and not direct to the ECM.

Edited by Shainer
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16 minutes ago, trreed said:

Yeah, that’s sucking air hard. If the quick connect is fully clipped onto the suction port of the basket, next is to look at the quick connect to pushloc adaptor and see if that connection is letting air in

You think that is just air?  I've heard them when the whine changes and can get quite loud but not like marbles are being knocked around.

 

I found some other videos on the net with the same sound.  Of course not a single one has any info on what the problem was.

Edited by Shainer
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By it only happening when warm leads me to think VP. Has the fuel level stayed aboive 1/2 tank? It’d have to be a pretty good sized leak on the suction side to let that much air in and it’d have to be all in the fuel module somewhere. When’s the last time the filters have been changed? Water seperator drained?

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7 hours ago, Shainer said:

You pumping #2 diesel or 2# rocks through there?  That sounds terrible, and a lot like physical interferences in the pump.  What size fuse is on there?  Ever blow one?  Please tell me you installed the relay and not direct to the ECM.

Never blew a fuse and not sure what fusenim running. I don’t remember hooking anything to the ecm. 

 

7 hours ago, trreed said:

Yeah, that’s sucking air hard. If the quick connect is fully clipped onto the suction port of the basket, next is to look at the quick connect to pushloc adaptor and see if that connection is letting air in

That connection is good. Reclamped it down very tight.

 

7 hours ago, notlimah said:

By it only happening when warm leads me to think VP. Has the fuel level stayed aboive 1/2 tank? It’d have to be a pretty good sized leak on the suction side to let that much air in and it’d have to be all in the fuel module somewhere. When’s the last time the filters have been changed? Water seperator drained?

Fuel level has stayed mostly above 1/2 accept when I fueled the truck 2 weeks ago. Filters have I think 6k on them. @trreed how many did you say there was? Yes I drained the water separator. 

7 hours ago, trreed said:

Yeah, that’s sucking air hard. If the quick connect is fully clipped onto the suction port of the basket, next is to look at the quick connect to pushloc adaptor and see if that connection is letting air in

Got a video of what they’re supposed to sound like? 

 

7 hours ago, notlimah said:

By it only happening when warm leads me to think VP. Has the fuel level stayed aboive 1/2 tank? It’d have to be a pretty good sized leak on the suction side to let that much air in and it’d have to be all in the fuel module somewhere. When’s the last time the filters have been changed? Water seperator drained?

Iv been thinking vp all along because of symptoms only while warm but I got tonexhaust the other ideas before I cough up 1k. Im going to run a clear hose from the factory canister to the IP and see if there’s air in them lines. 

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