Originally Posted by Supercharged Guy
I have 5,750 on mine and something is wrong with my fuel system or atleast thats what vince said.
My car kinda stutters/bogs at a low gear just puttin' around town, vince said he thinks it's a fuel pressure reg. or a fuel pump
I put some thought into this and came up with the following:
Since GM started putting the fuel pressure regulator into the fuel pump module, I've found that typically a bad fuel pressure regulator will cause an extended crank. When a regulator goes bad, the fuel pressure will drop very quickly to 0 when the vehicle is shut off. However I haven't noticed any lean conditions caused by this failure. This is reinforced by the fact that in a returnless direct injection system, the high pressure fuel pump provides the actual pressure needed and is electronically controlled.
Its possible that pump output could be low but that'd be more likely to show up under hard acceleration. The volume of fuel needed to drive the car at low speeds isn't great. So a bad fuel pump would be more likely to show up as a lean condition high in the RPM range.
I'm not going to claim that your mods are causing the problem or that its a tuning issue because I can't physically look at the car. I also don't claim to know everything and it could possibly be a bad pressure regulator or pump, I've seen stranger things happen.
Just thought I'd give my input based on the experience I've accrued over the years.