My name is Todd I have a 95 S-10 with a 4.3 with central mfi. My check engine light is on and I cant get any dtc from it. Ive tried 2 diagnostic tools and tried the paper clip method also but cant get anything to flash. My blazer runs great when it is cold but 3 min. after start up it starts to miss and eventually runs like crap. please help me figure this one out. Thanks Todd

 

Your 95 will have one of two different computer controls, we need to know which one you have. Do the spark plug wires connect vertical or horizontal to the distributor cap?

 

The 8th character in the VIN tells what engine was originally installed in the vehicle. There are 5 different types of 4.3L fuel injection systems and 4 different types of engine control systems used on them.

The “Z” engine code, 1987 through 1995, uses Throttle Body Injection, (TBI) and OBDI engine controls. It uses two injectors mounted in the throttle body. The injectors alternate when firing. Each injector feeds every other cylinder in the firing order. With the engine running, fuel pressure must be 9psi to 13psi.

The “W” engine code, 1992 through mid 1995, uses Central Multiport Fuel Injection, (CMFI) and OBDI engine controls, (late 1995 engines are controlled by OBD1.5). Both systems use one centrally located injector inside the plenum. There are 6 fuel lines connected to the injector; at the other end of each line is a plastic nozzle with a spring loaded poppet valve. Each line is routed to a machined passage in the lower intake manifold that leads to the back side of the intake valve. The injector is “batch fired” meaning it feeds all cylinders simultaneously. Fuel pressure spec for 1992 through 1994 is 55psi to 61psi with the ignition in the RUN position, engine OFF, and the fuel pump running. It must remain above 50psi for 3 to 5 minutes after the fuel pump shuts off. Fuel pressure spec for late 1995's is 58psi to 64psi with the ignition in the RUN position, engine OFF, and the fuel pump running. It must remain above 53psi for 3 to 5 minutes after the fuel pump shuts off.

The “W” engine code on 1996 and newer uses Central Sequential Fuel Injection, (CSFI) controlled by OBDII engine controls. There are 6 injectors that are centrally located inside the plenum. There is a fuel line connected to each injector; at the other end of each line is a plastic nozzle with a spring loaded poppet valve. Each line is routed to a machined passage in the lower intake manifold that leads to the back side of the intake valve. The injectors are fired sequentially, just like the firing order of the engine. With the ignition in the RUN position, engine OFF, and the fuel pump running, fuel pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after
+ what Captain said


Todd google Clean EGR valve 1995 Chevy Blazer.