The spec sheet for the GMPP engine in my s-10 shows max rpm 5700. A new problem came about a couple of weeks ago and troubleshooting has been unsuccessful thus far. The engine runs strong from idle to about 4,000rpm. It seems that it shuts down and comes back to life after it falls to 3200 to 3500rpm. This occurs mostly WOT acceleration and under a load. Parked in the drive way it will rev to the limit with short bursts of throttle. I have adjusted valves, timed, new performance coil and module, fuel lines, filter, havent changed wires or plugs yet just getting disgusted with the whole thing because its embarrasing when you kill a nissan at the light but then get SMOKED when the shut down comes along. This engine really does justice for the little truck off idle. Would just like to see more top end. Any suggestions?