ok i got a 89 iroc with a 350TBI i hav a new fuel pump, spark, and persure on te rail and the injctors are shootin fuel out. It will run on ether but it mont fire on just fuel. what could be my problem? Any answers let me kno thanks.

 

igntion timing could be off, exhaust could be plugged up (possibly), or the spark could be too weak. could also be bad intake gaskets. whats the history on the engine?

 

Like Micro said, if you are getting fuel, what about the other side of the triangle, (Spark, Oxygen), How old's the air filter?