Hi, I’ve owned this car for 2yrs…. 89 Iroc Z, automatic with a 5.0L 305 TPI. Overall the car runs strong but having some issues with it running too rich with a strong smell of gas and only getting about 100miles/tank. Also during start it blows bit of black smoke for few seconds. I’ve replaced many basic tune up related parts like: plugs/wires, O2 sensor, ICV, disconnected EGR, fuel pump, fuel filter, fuel regulator, replaced coolant, cleaned throttle body. My next plan is to replace the injectors and was told to install 19lb injectors. I wanted to know if I should consider replacing or updating any other parts while the intake and fuel rails are opened up during injector replacement?? Any help would be really appreciated!!

 

make sure the regulator diaphragm isn't leaking and you may want to replace the gaskets and fuel rail orings

 

Disconnected EGR will cause you problems unless EGR is disabled in your tune. I'd consider reconnecting / replacing any faulty EGR components while you have the plenum off. A datalogger will help you diagnose poor running conditions. I recommend using the more expensive Delphi injectors as they seem to play nicer with the stock tune.