Soduh1

ok so its defenetly not a back pressure issue nor a fuel issue... i found that when we remove the vacumm hose from the air ressure regulator the motor dosnt stall out but as soon as you disconect the vacuum house from the valve cover it stalls out after 2-3 seconds. also not sure if this is an issue or not but with the key in the on positioin if the flap in the maf is moved the injectors dump gas with no noticeable pulse. any advice is helpful and appreciated

i have an issue with my fuel injected z. i just got an exhaust installed but before that the car ran fine. now my car will idle fine but as soon as the throttle is pressed the engine stumbles. dosent die but if u hold down the throttle the car will stumble for 2 or 3 seconds the rev up. any ideas? could this be a backpressure issue?