Ok I have diagnosed that there is a significant drop in fuel pressure after the engine is turned off. I just removed the top part of the intake and was wondering if anyone has any input for me as to what component or components are at fault. Is there anything I can test for while the top intake cover is off?

 

I'll reply here instead of in PM. I hope you don't mind me quoting your PM.

Ok. So to answer some of the questions both in your PM and in the post above... A lot has been answered in various other posts, but I'll reiterate for you. For the MFI conversion, you only need the updated spider assembly (which includes the fuel metering body, fuel pressure regulator, and all 6 MFI injectors). The updated spider is a direct replacement for the SCFI spider. Nothing else needs to be changed. I used genuine GM parts when converting my old Bravada and since I was replacing my lower intake manifold gaskets at the same time, I had replacement o-rings for the upper plenum seals. I'm not sure why Advanced Auto's website is calling for replacement of the bracket and gasket pack. The gaskets (o-ring type seals) really only need to be replaced if they are damaged. If, after inspecting them, you find them to be defect free, then it is not necessary to replace them. I used a bit of clean motor oil on all of the seals to ease assembly.

If you have the time, I am interested in seeing what they think is different about the stock bracket and their 'updated' one. The MFI spider I installed had eccentially the exact same metering body as the older SCFI spider. The only difference was that instead of having the electronic injectors housed in the metering body, the MFI spider moved them out to the intake runners in place of the problematic poppet nozzles.

GMPD.com took FOREVER in my experiences with them. Granted I have only used them twice, but with alternatives like RockAuto.com or my local AC Delco distributor, I'd rather not use GMPD.com other than for their online catalog.

 

Kyle, Thanks for your input. I did look on that RockAuto.com site and i see that the mfi conversion on there is also calling for the new bracket. Might just be a way for them to make a little more $. It looks like I am going to get this assembly from RockAuto.com because it is pretty well priced and I really do not have the time to let this thing sit and wait for parts to come from GMPD.com

Thanks Again