Good Afternoon Folks! Been trolling forum for information for years without need to post so thank you all for the support & information! Could not seem to find similar thread to current issue & any direction or ideas would be greatly appreciated & thank you in advance!
Apologize this is a long one....
2017 Silverado 120,000 miles, current build:
Gen V L83, Bored 3.80" stroked 3.858 to 350 CI
Mast motorsports rotating assembly
L86 heads, dual valve springs, aftermarket rockers & arms
L86 intake & throttle body
TSP stage 3 cam
LT1 HPFP with CC spring & lash Cap
LT1 Injectors
Long tube headers
DOD delete
All new sensors & battery
Tuned by Pat G.
Concern started & appeared to be failing stock FP shortly after dropping in engine, break in and first run began losing fuel pressure & dying but only after running great for 5 - 10 minutes.
Sent FPM to DeatschWerks to install 340 LPH fuel pump which they tested & stated would support 900 HP @ 60-70 PSI in this trucks stock configuration. Installed & ran good for about 10 minutes lose pressure & die. start back up and would run amazingly for about 2-3 minutes then die over & over & over so would get us back to shop which was nice....
Contacted DW & they recommended hard wiring pump directly from battery. Dropped tank again installed 12 gauge hard wire directly connected to battery with 30amp fuse & relay triggered by stock FP power source. Exact condition remains
Contacted DW & they stated likely supply restriction, inadequate venting or electrical signal issue. Dropped tank again verified venting, supply line, Evap system & wiring integrity. everything in good working condition. bypassed FP module PRV, installed DW regulator set to 70 psi & return line, tested & Condition still exists only this time when condition begins can see regulator gauge bouncing from 0 to 30 psi for a moment then 0 to 10psi
Dropped tank again installed single 450LPH Aeromotive pump & module, deleted FPCM, Removed stock fuel lines installed An6 braided lines inspected & tested entire system venting, pressure volume wiring amperage & voltage outputs. Truck ran great & did not die at any point as before however while accelerating as soon as 3500 RPM reached engine falls on face. was Logging live with HPT VCM (attached) PG4 cutting out 3500.hpl& observed LPFP drop to zero & exactly 3500 RPM which in turn the HPFP drops to zero & engine cut out. let off throttle then immediately back to 70PSI everything back to normal. Engine would never die just cut out & stutter. Attempted to make past 3500 rpm repeatedly with no difference
Reached out to tuner explained everything above & he stated not tune because was able to rev out during first run with stock LPFP before it went out...
No diagnostic codes present & no indicators of failures or failing sensors/components that we can identify so needless to say we are extremely perplexed... Has anyone experienced something similar???
Is it possible a tune parameter is causing cutout to occur?
Single 450 LPH not enough do we need to add second FP?
Are we overlooking something fundamental here?
Thank you in advance for taking the time to read through this mess and for any advice regarding this matter!!!
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