Nissan Repair: 97 nissan pickup, mass air flow sensor, mass air flow

Question
97 Nissan pickup running very rich I replaced the mass air flow sensor the map sensor cap rotor plugs wires. Nothing helped until i changed the BPT valve, this made the service engine light go off but it is still running very rich wont idel and runs much worse once warmed up.  help!!

Answer
Fred,

I would perform a leakdown test on the injectors.  Get a fuel pressure test set and connect to the fuel rail.  First, check the pressure with the engine running.  Then, turn off the engine and observe how fast the pressure drops off.  I bet instantly will be the answer.  And, if so, you have injectors that are stuck open causing a really rich condition.  If this is the case replace the injectors.  You could just replace the defective ones but you will need to know which are running rich.  An easy way to do this is to pull he sparkplugs and observe which is really wet with fuel and black due to too much gas.