I was reading in my Helms manual the other day, and came across a passage talking about fuel cut-off (Yes I do read the Helms manual for fun :doh: ) . It mentioned that fuel cut-off is used to prevent overrevving, but also during deceleration, to improve fuel economy. The books mentions that the ecm cuts current to the fuel injectors. Does this mean the injectors aren't firing or just aren't opening very much? This sorta relates to the problem I've been having with funky sounds and piss poor performance from the engine, since and before the rebuild. I've noticed that the noises all stop or at least quiet down considerably when decelerating, and get noisy as all hell when I mash the pedal (up to my self imposed 4500 rpm limit ) or idle.
I'm going to be disconnecting fuel injectors and pulling plug wires tomarrow to hopefully determine whether an injector is bad or not, but understanding how the fuel cut-off works would help me out loads too. Thanks in advance. :thumbup:

 

When you are coasting the injectors do not fire.

98 GSRs have noisy injectors. Mine did. In fact, we did a poll here and I think we got 8 people with noisy 98 GSRs.

 

Noisy to the point of being mistaken for a rod knocking though? Something is definitely wrong, I'm just trying to learn the theory of operation of everything so that I can more accurately pinpoint it. Thanks for the info.