87 357 tbi. Idles great. After driving for 5-10 minutes blazer no longer wants to accelerate. It cuts out, if i let off the gas it continues to run and idle fine but that is it. If i have to drive it i have to take off very slow and continue. Even when parked it will not rev up. It acts as if there is a rev. limiter kicking in at around 2500-300 rpm.