alright i have a 02 monte with 3.8 i have a starting problem no matter if the engine is cold or warm. if i spray eather into the throttle body it will start but still a sluggish start. when running at idle its fine try and give it fuel it spits and sputters also falls on its face when i try to stomp on the gas when driving if u take off real easy its ok.parts that have been changed are mas,tps,02, used fuel pump,fuel filter,plugs,wires,coil packs,checked ignition mod,tested fine,removed cat,fuel psi regulater. fuel psi tested good with key on engine off and engine running.be fore changing the regulator. driving down the road its fine try to get into it it falls on its face and cuts out like its not running. the only thing in the fuel system that has not been changed are the injectors could this be the problem. anybody please help im tired of guessing.and spending money. starting not to enjoy working on cars.

 

Fp could be low on volume

 

Sounds to me like A bad MAF!
Replace it with a "NEW" AC Delco MAF..
Quick test to be sure.. unplug the MAF..start and drive the car... If it runs fine theres the problem..

OR
Your "Used" fuel pump is bad also!

is the CEL on?
(check engine light)

 

i think you might be right about the fuel pump the maf is new but its not a ac delco so ill try and unplug it.

 

I suggest taking that maf back and exchange it for an ac Delco maf. I also think the fuel pump may be weak. Don't have any vacuum leaks do you?

 

no sir i changed the intake gaskits and replaced the vac lines and checked it with carb cleaner and no leaks.( zzp aluminum intake set) do these engines not like differnt parts other than ac parts?maf is what im refering to

 

A lot of people had issues with brand new maf sensors that were not ac Delco for some strange reason.

 

well i unpluged the maf then started the car it didnt want to stay running so i pluged it back in and it ran so i dont think that is the problem any other ideas
thanks for the help

 

Low pressure fuel pump or dirty fuel filter are good things to check.

 

Another thing to overlook is the fuel pressure regulator. I'd check the fuel pressure this way u could rule out any fuel related problems