Page 2 of 2 FirstFirst 12
Results 21 to 25 of 25

Thread: LT4 FUEL PUMP UPGRADE. What needs to be updated??

  1. 01-29-2021 #21
    JANNETTYRACING
    JANNETTYRACING is offline
    Advanced Tuner
    Join Date
    May 2006
    Location
    Waterbury CT.
    Posts
    293
    That indicates a possible problem with what the fuel pressure sensor is seeing vs what the high pressure pump is seeing.
    Jannetty Racing Enterprises, Inc. Waterbury Connecticut Performance Shop, Dyno Tuning, Alignments, Speed Parts, Installations, Chevy, Ford, Dodge, Turbo Wastegate
    Performance Parts
    Reply With Quote Reply With Quote
  2. 01-31-2021 #22
    HeavyChevy305
    HeavyChevy305 is offline
    Advanced Tuner
    Join Date
    Dec 2015
    Location
    Miami,Fl.
    Posts
    290
    Quote Originally Posted by 67john98 View Post
    Thanks for the replies. This is the funny thing. Without the low side pump, the PW and HPFP pressures are much closer to "normal". By normal I mean 5-6 PW and much closer to the requested 2,900 psi requested pressure. Nothing else has changed, other than the addition of the low side pump.
    What was your low side dropping to before the aux pump? Your high side should still be fine up to e40 with your mods.
    2023 Ford Maverick 2.0T AWD
    Reply With Quote Reply With Quote
  3. 01-31-2021 #23
    67john98
    67john98 is offline
    Tuner in Training
    Join Date
    Dec 2017
    Location
    Sugar Land, TX
    Posts
    11
    Quote Originally Posted by HeavyChevy305 View Post
    What was your low side dropping to before the aux pump? Your high side should still be fine up to e40 with your mods.
    Prior to installing the aux pump, low side would drop into the 40's (E33). Attached is a 1/4 mile log before installing aux pump. This one shows pressures getting pretty low yet AFR still looks pretty good.

    I had another run where the car shut down and threw the low fuel pressure code (Also attached). I lowered the E to E30 for that run.

    The smaller file is the one where car shut down and the larger one was the good run.

    Gonna take car into my tuner on Tuesday to see if he can address the high-side drop. DSX was no help. Dave says he has seen this before (high side drop when aux pumps kicks in) but no idea how to fix it. Was quite surprised with all the tuning these guys claim!
    Attached Files Attached Files
    Reply With Quote Reply With Quote
  4. 04-21-2022 #24
    tfrost92
    tfrost92 is offline
    Tuner in Training
    Join Date
    Sep 2020
    Posts
    14
    Quote Originally Posted by Ben Charles View Post
    Make sure the axis is the same as the stock OS, I do change these from time to time, but you have to know what you?re doing or you?ll have problems
    I?m gathering parts for an lt4 fuel system swap into a 17 L86. Should I not copy all fuel system related tables from a lt4 file including changing axes?
    Reply With Quote Reply With Quote
  5. 04-28-2022 #25
    Brianw36
    Brianw36 is offline
    Tuner
    Join Date
    May 2017
    Location
    North Florida
    Posts
    80
    "Gonna take car into my tuner on Tuesday to see if he can address the high-side drop. DSX was no help. Dave says he has seen this before (high side drop when aux pumps kicks in) but no idea how to fix it. Was quite surprised with all the tuning these guys claim!"

    67John98

    Were you ever able to get this resolved?
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »