LS Run Stand - Fuel Pressure Issue
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Teching In
Joined: May 2021
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LS Run Stand - Fuel Pressure Issue I made a universal, portable LS run stand that allows me to start and monitor LS engines at junkyards, driveways, or car shows. My fuel cell uses an OE in-tank S10 fuel pump that should deliver 60psi (VIN W) before the regulator on the fuel rail. However, I only get 52psi key on, not running and 45psi at idle. Engines idle fine but will not rev. Before I buy/make a better fuel cell and fuel delivery system, what am I missing that's preventing engines from revving past 750rpm? What I have and have checked so far:
Is my pump bad or am I missing something?
- Stand alone harness with under hood fuse buss eliminated but OBDii port functions
- Pump filter sock is clean, pump is 1/2 submerged in fuel
- I have pressure fittings/gauges at the pump and at the fuel rail, both read the same
- Injectors are dry at 52psi
- Actively misfiring on all cylinders at idle on HPTuner scanner
- No thrown codes other than P0300
- Pump ground has continuity, 12v at the hot grey wire from stand alone fuse buss. Tank fuel level and low voltage signal wires are not employed.
- LS truck return fuel rail set up (not returnless)
- Converted to drive by cable with wiring harness mods and ECU rewrite
- EVAP and EGR deleted
- WB O2 sensors are on, MAF in use
Is my pump bad or am I missing something?
