96 blazer v6 it has spider injection. i had replaced fuel pump thinking it had the wrong fuel psi, also changed the spider injection and still raw gas is going out the exhaust and also fill up cyclinders 6 an 5. i all ready check for leaks in maniflod and fuel lines....no leaks. i give up on ideas

 

If you have fuel coming out of the exhaust and flooding out cylinders 5 and 6, then you have a leak internal to the engine. The fact that it is flooding out 5 and 6 tells me that the FPR is shot. To verify, remove the fuel lines from the top of the engine, remove the upper plenum, and reinstall the fuel lines. Pressurize the system and look for leaks.

 

ya i had raw fuel comin out my tail pipe when my fuel lines inside the plenum were bad. def take the upper plenum off and look inside. i would turn the key to the on position with the upper plenum off so u send pressure to the injector and can see if u have a leak in the plastic fuel lines inside the plenum.

 

The 96+ are SCFI motors. The only plastic fuel lines are between the injectors and the poppet nozzles. The fuel feed and return lines are metal and are on the exterior of the intake plenum.