i jus did a 91 ls swap in my 89 ef hb and wen it starts u have to keep ur foot on the gas to keep it runin and wen u rev it up it only goes to 3grand and pops and carrys on like a rev limiter but i have the rite ecu and everything anyone plz i need to have the car workin by tuesay the 4th

 

I had a similar problem once. Turned out to be a dead fuel injector.

Though if it can be fuel it can also be spark.

 

Mine did that and it was the fuel filter