marc1130

UPDATE: I just finished the trap door modification. I put a Walbro Fuel Pump in (255LPH) from TRE Performance only $99. The harness was plug and play. The pump fit perfectly in the LT1 fuel pump bucket with the provided sock. I bought a 10" flex hose from autoperformanceengineering along with the foam that goes around the pump body to prevent rattling. I zip tied the bucket lid with nylon zip ties instead of glueing it. Fuel pressure stays at a constant 43 psi at WOT all the way to redline, no hesitation or misfires. The car runs like new and has a general increase in power across the board. I am very satisfied with the repair, and glad it wasn't the optispark.

marc1130

Well despite fixing the fuel pressure issues, the misfire was still present. I went ahead and changed the opti last week with a GMPP unit. I used redloctite on the rotor screws and copper rtv on the optical section and the cap section to make a air tight nice seal. While I tore into the front I got ambitous and removed the crank hub changing the three seals in the timing cover. Now it is running like new with no misfires through the whole range of rpms. It is amazing how much difference the fuel pump and opti make! Any other suggestions for a high mileage car?