My fp gauge readings and no start issue has me lost. Originally, car began backfiring & rough starting while backing out the driveway one day. Eventually, it wouldn't start at all. Pillar FP gauge displayed 0 fuel pressure and wouldn't move with key on nor when trying to start.

Eventually replaced fuel pump, filter, fuel pump relay, fpr. Pillar guage (supercharged setup) shows 31psi and stays when trying to start. Car just turns over. Occasionally it will fire for a quick second but just die or continue to turn over. Used a FP test gauge with key on, shows 32psi, pillar gauge shows 0psi. Checked injectors for leaks, no injectors are leaking. Checked new fpr for leaks, none.

I even replaced the opti, swapped coil and ICM, new coil wire. Even tried to swap obd1 comp with spare obd2 ecu used for smog, Still no start. Best is a quick idle then it dies.

Today, I was able to get 20psi from FP test gauge, rose slowly to about 35psi while trying to start. Still doesn't fire up though and pressure dropped right back to 0. Pillar gauge shows 30-35psi while attempting to start.

Things that were changed prior to problems were braided fuel lines from rail to hard lines under driver seat (I don't see/feel any leaks). Drove that way fine for at least a few hundred miles.

LT1 355, M6, obd1 swap, vortech s-trim, bolt-ons, stock ported heads, mild cam, 42lb inj...

 

The part about a "stock" fuel pressure gauge is a bit confusing - what stock fuel pressure gauge?

You indicate the pillar gauge shows 31psi when cranking, and does not move. Then you seem to indicate that once it fires for an instant, the pressure on the pillar gauge drops to "0". Since your pillar gauge is electronic, is it pssible you are losing the ground to both the gauge and the ignition? Or maybe a bad ground to the fuel pump?

Does the pump run and produce pressure if you use the fuel pump prime connector up by the PCM? That bypasses the relay and the PCM.

Have you scanned it for codes? If the PCM can't find the low resolution pulse from the Opti, it will shut down the fuel system.

 

Ok, I apologize for the messy post, I became confused reading it as well, but I've tried numerous changes and numerous attempts with fairly different readings yet the same results basically: no start.

I've tried to use an obd2 scanner using my obd2 ecu but it doesn't register any dtc codes??? The obd2 ecu is only used for smog and I haven't even used it yet actually.

I'll see if I can find an obd1 scanner