97 GTX 787 engine shuts off (all power) over 4000 RPM

[markrvp]

I bought a used 1997 GTX with 787 engine. I take it out and it dies on the water when I get over 4000 RPMs. I am going to be very specific in what I observed so hpefully you guys can troubleshoot it.

1.) Engine idled kind of rough @ 1600 RPM going out of the ramp area

2.) Right away speedometer doesn't work - neither analog or info center - tachometer and all other guages work fine

3.) I very evenly increase the throttle and when it hits right over 4,000 RPM the engine dies. THE INFO CENTER ALSO GOES DEAD. Total loss of power; I have to remove DESS key and insert it back on the post. After the two beeps I get a "12V LOW" message briefly. Restarts easily.

4.) I rev it up again and right at over 4000 RPM I lose all power.

5.) Restart, and now I rev it up and when I feel it's about to lose power, I let off the throttle and it goes back to idle, BUT NOT EVENLY - it drops to around 2000 RPM, and then over time drops to 1600 RPM. I can do this a bunch of times - right when I feel it's about to shut off I let off the throttle and it stays on.

6.) The engine will run at idle indefinitely. I can run it at around 3800 for a couple of minutes before it starts to shut off. If I hit the gas it will get going and then just die within a few seconds.

7.) ALSO, when I press the STOP BUTTON the INFO CENTER also shuts off. I thought it should stay on and I would continue to get warning beeps that the key was connected.

8.) Back home I hooked the engine up to a hose and on the trailer it runs fine.

PLEASE HELP!!

Things my auto mechanic buddy did and tested yesterday:
1.) Compression - 1 cylinder is 150 psi, the other cylinder is 145 psi.
2.) Replaced the spark plugs

RAVE VALVES were replaced in 2006 - only 20 hours of use since then.

[markrvp]

This was a good problem - nobody had a guess.

Turns out it was a faulty fuel selector. I switched to RES and it stopped dying. It now tops out at 6500 RPM and 50 MPH.

[96XPSS]

Sorry man...you didn't give enough response time.

Some people are asleep at 11 pm...