At what point do you need to increase the fuel pressure?Also i have a Maf+ translator from a couple yrs. back.Can this be used to increase fuel pressure or do you need a adj.fpr.Btw my 02 readings were around 856-880.Any info. would be most helpful.

 

The fuel pressure is controlled ONLY by the fuel pressure regulator. You can not "set" it in the PCM, you can not set it with an MAF Translator.

Looking at the mods list, I don't see anything that would require an injector larger than stock. That would be the only reason to raise the fuel pressure - to increase the effective size of the injectors. The alternative is to simply buy the correct size injectors, and program the PCM for them. But there's nothing apparent that would require a larger injector.

O2 readings out of stock narrow band O2 sensors are not a good way to measure your A/F ratio. The narrow band sensors are not accurate at anything other than 14.7:1.

 

My next ? is then , at what point do you need a h.o fuel pump(Walbro 255 lph)or is stk. enough.As for that a/f ratio i need to get to a dyno & get some #,s which will be one of my priorities this yr.

 

I have no idea what the flow rating of the stock pump is. But again.... if your mod list is correct, the stocker will be fine. That is assuming its still in good shape after 16 years.

 

I,m going to hook that fuel pressure gauge to the w/s & test pump to be sure it holds the correct 43 psi @ wot.Is this correct?Thanks.

 

At idle, 43.5psi is with the vacuum compensation line disconnected from the fuel pressure regulator. GM accepts any pressure between 41-47psi as meeting spec. When you reattach the vacuum line, the fuel pressure will drop proportional to intake manifold vacuum. About a 6-8psi drop would be normal with a stock cam, less drop with a more aggressive cam. Out on the road, max RPM/max engine load, the pressure should not drop below 40psi.

 

Thanks INJUNEER for that helpful info about trying for at least 40 psi fuel pressure.