Fuel pressure loss after sump install

[jtrakel]

Curious if anyone running a sump vs a straw system has seen a drop in their fuel pressure after install. I have FASS 165G that would always see 16-18 psi no matter how hard I step on the skinny pedal. I just installed a sump into my 54 gallon metal tank and now my pressure sits at 14 and dips to 12 at times.

 

Currently one fuel press sensor ~1 foot before the VP, and the Quad FP sensor is in the FASS pump, both reading within 1 psi of each other.

[Mopar1973Man]

Did you verify the gauge with a mechanic gauge? Hence why I made this bracket. 

 

 

Now I can unscrew the sender add a tee the hook up my test gauge and hang it on the door. Now I can verify mechanic test gauge against the electric to verify the sender is good. 

The other reason for the bracket. The remote mount of the sender are away from the fuel system a total of 5 to 6 feet of tubing. At the source point I've got a snubber and 5 to 6 feet of tubing. This allows the pulses to die out as they travel up to the sender. I've got YEARS on this fuel pressure gauge now and still working flawless. I just want to change the reaction speed of the needle to slow it down. ISSPro programming software and just plugin the programming cable.

 

[jtrakel]

I have not hooked up a true mechanical gauge at this time, I may have to find one and try however, having both sensors reading the exact same numbers in two separate locations makes me believe they are working as they should.

 

Fuel issues seem to be the current flavor for my truck, ever since I installed my injectors I've had a stutter under light throttle and idle. With hurricane Sally circling over me right now i'm unable to really get out and trouble shoot but I've uploaded a video of the idle and light throttle application.

 

Plan is to reset the APPS check all lines and re-seat the injectors. I'm unable to send my injectors off for pop testing at this time as I am about to drive across country next week and cannot afford the down time (AL to WA). Any other suggestions as to what could be causing this rough idle? It does this regardless of where I have my tune set or what tune i'm running lvl 0 to whatever level I select on tunes from this site and other places.

 

 

Edited September 16, 2020 by jtrakel
Video added

[Mopar1973Man]

 

Videos do load... 

 

What is your engine load on al ive data tool or Quadzilla?

 

What is your idle speed without your foot on the throttle?

 

Any error codes?

[jtrakel]

Engine load at idle is between 10-15%
 

Engine RPM is 750-800 on my quad. There is a disparity between my quad and gauge cluster as the cluster reads about 500RPM at idle. Currently have a new cluster on the way.

 

No error codes.

[Mopar1973Man]

Too squirrelly... Should hover 795 to 805 RPM. Target is 800 RPM. I would consider testing injectors.

Edited September 16, 2020 by Mopar1973Man

[jtrakel]

2 hours ago, Mopar1973Man said:

Too squirrelly... Should hover 795 to 805 RPM. Target is 800 RPM. I would consider testing injectors.

Just went and idled the truck again and I’m hovering right around 795-805. Guess I have to big of a range earlier 

[LorenS]

If this pressure drop happened immediately after the sump install, I would start with a filter check, no matter how much you cleaned the tank.  Any and all remnants now have gravity assisting them in their quest to enter your fuel system versus settling on the tank bottom.

[Mopar1973Man]

Ok back on track. Fuel pressure wise I would look at for any kinks in the hoses, any loose suction lines might be weeping air, etc. 

[jtrakel]

47 minutes ago, LorenS said:

If this pressure drop happened immediately after the sump install, I would start with a filter check, no matter how much you cleaned the tank.  Any and all remnants now have gravity assisting them in their quest to enter your fuel system versus settling on the tank bottom.

 

Brand new filters with the replacement, once the weather calms down I plan to check the FASS pump doing the 5-gallon bucket test on their site.

 

47 minutes ago, Mopar1973Man said:

Ok back on track. Fuel pressure wise I would look at for any kinks in the hoses, any loose suction lines might be weeping air, etc. 

 

Awesome thanks for the info, I'm going to recheck everything I worked on this past weekend tomorrow hopefully!

Edited September 16, 2020 by jtrakel