What could be wrong?

It could be that your hitting the rev limiter and its shutting the fuel off to your engine. The only way that you would ever reach 6K though would be to have an RPM extender though or aftermarket ignition, because I believe the stock auto computers only alow the engine to be reved to ~5,600 - ~5,800. Thats at least where mine bounces off the rev limiter. It would make a popping noise like a backfire if you were doing this.

WhiteStallionGT said:

I then power.

Click to expand...

If you meant "I then LOSE power", it's definitely your rev limiter kicking in.

If you are hitting the rev limiter by simply punching it in drive, the problem can be solved by getting a chip or a stand alone unit like the TwEECer. I have heard people with auto's love the TwEECer becauase you can change line pressures in the tranny and such. The reason you are now hitting the rev limiter is because before your 4.10's, your cars computer could send the signal to shift and the approx. 1 second delay would not interfere with your rev limiter because your RPM's weren't climbing as fast. But with the 4.10's, the lower gear ratio allows for the car to gain RPM's at a much faster rate, thus that 1 sec. delay in shifting allows the RPM's to bounce the limiter. The only other thing you could do I believe would be to replace the stock valve body with an aftermarket one or buy a shiftkit, which in turn makes the shifts happen at the snap of your fingers, eliminating the problem.

i hate rev limiters!!!!!!!