I've finally unleashed the Beast in my '00 ECSB 5.3L 4x4 and have to ask this stupid question whether for motivation, vindication, support?? LMAO..

At 158k on the clock....should I just go ahead and R2 the old one?

I'm feeding approx. 400+ flywheel, Custom Comp cam, 3.5" ORY 1 3/4" SS Long tubes, Custom SS FlowMaster design exhaust, extensive head work and radical ported intake and TB. Stage 4 65E and Circle D at 3600, Black Bear tune.

The reason why I shared the specifics is because if the consensus says change it out, the 2nd part of that answer is do I upgrade the pump?? Don't want to leave performance on the table, but not necessarily looking for any more either.

This is what we do when we're a Raven fan this season!!

 

I hooked up my hi dollar digital/analog fuel pressure gauge to the OEM fuel shrader port and I'm reading 42-44 psi at idle with the stock pump. I get the persistent P0300 CEL and flashing CEL. It's a 2000 5.3l return style system with stock oem injectors.

My question is what should the idle psi be? As soon as I drive it and mat the loud pedal, the light starts flashing, then sets and there's a profound miss. The only DTC it produces is P0300. Confirmed no vacum leaks and all sensors are new AC Delco.

Thoughts on what the problem could be? Black Bear says Lean/rich, rich/lean threshold values need to be adjusted in the tune.

Help!!

Thanks and Happy New Year!

V1

My question

 

I think the pressure should be between 55-62 psi. I would start by changing the filter, and then rechecking the fuel pressure.

 

That reading is correct. What does it say when you prime the key with the engine off?

0300 is random misfire...in 95% of cases I have seen its ignition related...burnt wires, cracked plugs, something like that.

 

The only numbers I've seen with both the system primed, engine not running and running is 42-44 psi. Fuel filter is a new Delco.

Ignition is all new. Taylor wires, MSD coils, NGK Platinums gapped @ .040. I'm one truck bed mount bolt/nut assy. away from allowing the installation of an AC Delco replacement. When it warms back up mid to later this week I'll cut the bolt off and raise the bed. Too cold to lay on the concrete and just perfect for sipping shine by the fire.....

I'm hoping it's the low pressure.

 

Try the stock coils on there and double check no wires are touching the headers...

 

OEM state's Key On Engine OFF 55-62 PSI

From what I remember on my 2000, OEM fuel PSI spec on a Return Style is 48-52 PSI While running at Idle. Remove the Vacuum regulator hose from the regulator and it should raise up by approx 8-10 PSI to 58-62PSI

Mine was a solid 50PSI at idle and would jump to 58 PSI when the vacuum hose was pulled from the regulator at Idle.