Hello i have a 95 blazer with the 4.3 it runs really rough at idle and until it gets to high rpm when its on the freeway over 30Mph then its fine just did plugs and wires smells like raw fuel and burns fuel at an intence rate any ideas thanks in advance

 

Provided your engine looks like this:




Check fuel pressure and leakdown at the service port near the distributor. When you initially turn the key to the run position, (don't start the engine) the pump will activate for ~2 seconds and then shut off. Pressure must be checked while the pump is activated. On your 1995, with the key on, engine off, fuel pump running, fuel pressure must be 55psi to 61psi. AND, it must remain above 50psi for at least 10 minutes after the pump shuts off. Post your results.

 

Leaky injector assembly causing a rich condition?

 

Yup, very common with the CMFI system. Leaky fuel pressure regulator, or fuel lines to the injector assembly inside the plenum. Pressure and leakdown test results will confirm or deny.

 

Pressure tested it 55psi and holds

 

Everything i have researched lead me to believe its the spider injector under the intake

 

55psi while the pump is running is borderline, but technically OK. If the pressure remains above 50psi for at least 10 minutes after the pump shuts off, there are no leaks in the fuel delivery system, (pump, pressure lines from pump to the injector, the injector itself, fuel pressure regulator and spider nozzles. If there is a leak in the return line inside the plenum, it will not be detected in the leakdown test. You'll need to remove the plenum to visually check it for leaks. If either of the lines are leaking, the driver side of the plenum will be "washed" clean and have a golden color, (black is normal). From your description of the problem, I'd look very close at the return line in the plenum while the pump is running, (engine off) should be bone dry.




Here is what the "nut kit" looks like. They are sold as a pair.