Fuel mixture too rich at idle
Hey guys, I'm pretty new at this, but I have a question I've been trying to solve for about a month now. I have an '88 Blazer S10 2WD, 4.3 fuel injected. I've taken it to get smogged 4 times now, and it's failed every time. I've replaced the O2 sensor, the MAP sensor, the air filter, the Fuel Pressure Regulator, and I've taken off the Throttle Body and cleaned al of the valves real good. There are no vacuum leaks, or leaks on the intake manifold. The only area that the smog test fails at is Idle, and it's running between 700-800 ppm. After replacing the MAP sensor, my idle speed went down significantly, but still, the lowest reading was 703 ppm. It's running WAY too rich, and I think it's because the fuel injectors are jst pouring fuel into the intake, to the point where it's pooling on top of my valves. Was wondering if I need new fuel injectors? Also, I've run Lucas Fuel injector Cleaner through my engine. Any thoughts would be much appreciated.