I have put a 96 502 mpi in my 88 baja and I dont have a bravo drive resivor, so my question is what can I do with the blue and tan wire and the black wire that goes to the tank itself. And what is the tan wire for on the wiring harness?? I am having an issure where the motor like has a rev limiter at 3000 rpm, Im thinking these have something to do with it...

brown and black go to the resivoir it is a part of the alarm system

The other blue with tan tracer dead heads in the harness.

you can leave all of them detached, only the brown wire which would be attached to the level sensor in the drive resivoir would have an affect on the ECU setting Guardian mode. Guardian mode typically is set for 2500 RPM. Your issue sounds like it may be a temp problem. Remember what the gauge reads on the dash is not what the ECU sees from the engine. There are 2 ECT coolant sensors one is a single wire lead (feeding the dash gauge) the other is a 2 wire connection with a metric weather pack connector (feeding the ECU).

The issue will happen at any time. Right off the trailer just startin the motor with no heat in it at all it will do it. It does it on plane it just sounds like a rev limiter. Which makes me believe its not temp related...