Is there a common or frequent problem with fuel injection or sensors on a 1994 S-10 Blazer?

Answer 1

Absolutely. The problem is common with all the GM vehicles made between 1992 - 1995, that have the 4.3L Vortec vin code "W". The 4.3L Vortec has a CPI (Central Port Injection) system that has proven to be quite problematic. These injection systems consist of a large fuel injector that has tube going to each cylinder (six total). This injector is located in the plenum. (must remove upper intake to see it) The problem with these systems is that they develop leaks, these leaks occur in either the FPR (fuel pressure regulator) mounted on the side of the injector or the internal fuel lines leading to the injector assembly (GM has decided to refer to these internal fuel lines as a "Nut Kit" for some reason). The FPR is located on the passenger side half of the intake, and the nut kit is located on the driver side of the intake. The cylinders on the side that develops the leak, get flooded by fuel causing a rich condition. This rich condition can cause the engine to run rough, create a strong smell of raw fuel, set O2 sensor codes, cause excessive carbon build up that plugs the EGR valve, set EGR codes, and/or cause raw fuel to enter the oil which destroys the engine. I will add links to the right that have more information about the problem, and detailed instructions on how to fix it. Look for "92-95 4.3L Engine info", "4.3L Vortec CPI and Nut Kit Replacement", and "4.3L Vortec Fuel Pressure Regulator Replacement"