studder under boost

[Little6pack]

Looking at a GN today, Known problem is a studder under boost.

My guessing would be a good spring cleaning needs be done.

any other ideas as to what could cause this. (coil, plug, plug wire)?????????

 

[turboman38]

vacuum leak??

 

[2QUIK6]

Without a scan tool, it could be any of the above, but all fairly easy to remedy as long as there is no rod/bearing knock that is audible from continued use with the problem/sputter not corrected.
Could also be weak fuel pump and the sputter is actully knock and timing being removed (this would be the most damaging). The other likely culprit would be plugs/wires/coil/ignition module or bad ground wire attached to the back of the head or bad ground strap connecting block and frame.

 

[acoen]

I just fixed my problem today. I was doing a spring cleaning and replaced my fuel pump and coil while I was at it. The car ran ok before, but would surge and sputter at times, I replaced the coil made it worse, turned out that the new coil was defective, in other words check the coil even a new one. The main problem that I found when I replaced my fuel pump, the sock in the tank was completely collapsed and plugged. Sputter and popping has disappeared. Car runs great.