87 k5 blazer. Just rebuilt the motor. 357. TBI. Basically stock besides being bored. Everythin worked great until yesterday. Drove around for about 5 minutes then it would not want to accelerate. There was no problem idling. Checked all of my wires and none were crossed and all were hooked up. Even in park it would not rev. acted as if there were a revlimiter and it would have been activating at around 2500 to 3000. Took it back home and parked it. Started it this morning and it ran great for about 10 minutes then did the same exact thing.