ok, this is fresh rebuilt motor, only ran for an hour or less. the motor starts easily, but stall if I don't give it gas. when I put ignition on to crank the car without giving gas, it rev up to 2000 rpm, and then stalls quickly, like run out of gas or something like that. but I keep pressing gas petal, it will keep running at 2000 rpm. again, it will cut off if my foot is off the accelerator.

I have zip tired all vacuum hoses, change injectors O rings, insulators. any idea?

I thought about the timing, but bad timing will only cause rough idle, not stall. I cleaned the BAC a little bit before I put it back. didn't check TPS yet. but again, tps will cause rough idle, right? vacuum leak? it got to be a big one to stall the motor. but I don't see it anywhere.

thanks

 

oh, this is s5 n/a motor.

 

i had the same problem, and i hope you didn't make the same mistake as me. check your upper and lower intake manifold for large cracks, especially up around where the lower manifold bolts to the engine. If the gasket was not on properly, when the bolts are tightened, it cracks the edge of the manifold.